Cryptography and Network Security Sicurezza delle reti e dei sistemi informatici SSL/TSL

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Cryptography and Network Security Sicurezza delle reti e dei sistemi informatici SSL/TSL"

Transcription

1 Cryptography and Network Security Sicurezza delle reti e dei sistemi informatici SSL/TSL

2 Security architecture and protocol stack Applicat. (SHTTP) SSL/TLS TCP IPSEC IP Secure applications: PGP, SHTTP, SFTP, or Security down in the protocol stack -SSL between TCP and applic. layer - IPSEC between TCP and IP 2

3 SSL/TLS intro Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL), are cryptographic protocols that provide security for communications over networks TLS and SSL encrypt the segments of network connections at the Transport Layer end-to-end 3

4 SSL/TLS intro, continued Several versions of the protocols are in widespread use in applications like web browsing, electronic mail, Internet faxing, instant messaging and VoIP TLS is an IETF standards track protocol, last updated in RFC 5246, that was based on the earlier SSL specifications developed by Netscape Corporation 4

5 SSL/TLS intro, continued 2 SSL/TLS allow client/server applications to communicate across a network in a way designed to prevent eavesdropping, tampering and message forgery provide endpoint authentication and communications confidentiality over the Internet using cryptography. RSA security with 1024 and 2048 bit strengths 5

6 main threats addressed eavesdropping = the act of secretly listening to private conversation tampering = the act of altering something secretly or improperly message forgery = sending of a message to deceive the recipient as to whom the real sender is 6

7 SSL/TLS intro, continued 3 In typical end-user/browser usage, TLS authentication is unilateral: only server is authenticated, but not vice TLS also supports mutual authentication provided that partners diligently scrutinize identity information 7

8 SSL/TLS intro, continued 4 Mutual authentication requires that the TLS client-side also holds a certificate (which is not usually the case in the enduser/browser scenario) Unless TLS-PSK, the Secure Remote Password (SRP) protocol, or some other protocol is used that can provide strong mutual authentication in the absence of certificates 8

9 SSL/TLS intro, continued 5 TLS involves three basic phases: 1. Peer negotiation for algorithm support 2. Key exchange and authentication 3. Symmetric cipher encryption and message authentication 9

10 SSL/TLS intro, continued 6 During first phase, client and server negotiate cipher suites, which determine ciphers to be used, key exchange and authentication algorithms, as well as message authentication codes (MACs) key exchange and authentication algorithms are typically public key algorithms, or, as in TLS-PSK, preshared keys (PSKs) could be used message authentication codes are made up from cryptographic hash functions using the HMAC construction for TLS, and a nonstandard pseudorandom function for SSL. 10

11 SSL/TLS: typical algorithms For key exchange: RSA, Diffie-Hellman, ECDH (Elliptic Curve Diffie Hellman), SRP (Secure Remote Password protocol), PSK For authentication: RSA, DSA, ECDSA (Elliptic Curve Digital Signature Algorithm) Symmetric ciphers: RC4, Triple DES, AES, IDEA, DES, or Camellia. In older versions of SSL, RC2 was also used. For cryptographic hash function: HMAC-MD5 or HMAC-SHA are used for TLS, MD5 and SHA for SSL, while older versions of SSL also used MD2 and MD4. 11

12 SLL/TLS and digital certificates The key information and certificates necessary for TLS are handled in the form of X.509 certificates, which define required fields and data formats. 12

13 how SSL/TLS works 1/5 Client and server negotiate a stateful connection by using a handshaking procedure. During handshake, client and server agree on various parameters used to establish connection's security Handshake begins when client connects to TLSenabled server requesting a secure connection and presents a list of supported ciphers and hash functions From this list, server picks the strongest cipher and hash function that it also supports and notifies client of the decision 13

14 how SSL/TLS works 2/5 Server sends back its identification in the form of a digital certificate X.509 Client may contact the CA and confirm that the certificate is authentic and not revoked before proceeding modern browsers support Extended Validation certificates 14

15 how SSL/TLS works 3/5 For generating session keys used for secure connection, client encrypts a random number (RN) with server's public key (PbK), and sends result to server. Only server is able to decrypt it (with its private key (PvK)): this is the one fact that makes the keys hidden from third parties, since only the server and the client have access to this data. 15

16 how SSL/TLS works 4/5 Client knows PbK and RN, and server knows PvK and (after decryption of the client's message) RN. A third party may only know PbK, unless PvK has been compromised. From the random number, both parties generate key material for encryption and decryption. 16

17 how SSL/TLS works 5/5 This concludes the handshake and begins the secured connection, which is encrypted and decrypted with the key material until the connection closes. If any one of the above steps fails, the TLS handshake fails, and the connection is not created. 17

18 SSL (Secure Socket Layer) transport layer security service uses TCP to provide a reliable end-to-end service originally developed by Netscape version 3 designed with public input subsequently became Internet standard known as TLS (Transport Layer Security) SSL has two layers of protocols 18

19 SSL Architecture 19

20 SSL Architecture SSL session an association between client & server created by the Handshake Protocol defines a set of cryptographic parameters maybe shared by multiple SSL connections (renegotiating can be onerous) stateful SSL connection a transient, peer-to-peer, communications link associated with 1 SSL session stateful 20

21 parameters defining session state Session identifier arbitrary byte sequence chosen by the server to identify an active or resumable session state Peer certificate X509.v3 certificate of the peer. This element of the state may be null Compression method The algorithm used to compress data prior to encryption. 21

22 parameters defining session state Cipher spec Specifies the bulk data encryption algorithm (such as null, DES, etc.) and hash algorithm (such as MD5 or SHA-l) used for MAC calculation. It also defines cryptographic attributes such as the hash_size. Master secret 48-byte secret shared between the client and server. Is resumable flag indicating whether the session can be used to initiate new connections. 22

23 parameters defining connection state Server and client random Byte sequences that are chosen by the server and client for each connection. Server write MAC secret The secret key used in MAC operations on data sent by the server Client write MAC secret The secret key used in MAC operations on data sent by the client. Server write key The conventional encryption key for data encrypted by the server and decrypted by the client 23

24 parameters defining connection state Client write key The conventional encryption key for data encrypted by the client and decrypted by the server. Initialization vectors When a block cipher in CBC mode is used, an initialization vector (IV) is maintained for each key. This field is first initialized by the SSL Handshake Protocol. Thereafter the final ciphertext block from each record is preserved for use as the IV with the following record 24

25 parameters defining connection state Sequence numbers Each party maintains separate sequence numbers for transmitted and received messages for each connection. When a party sends or receives a change cipher spec message, the appropriate sequence number is set to zero. Sequence numbers may not exceed

26 SSL Record Protocol two main services confidentiality using symmetric encryption with a shared secret key defined by Handshake Protocol IDEA, RC2-40, DES-40, DES, 3DES, Fortezza, RC4-40, RC4-128 message is compressed before encryption message integrity using a MAC with shared secret key similar to HMAC but with different padding 26

27 SSL - Record Protocol 27

28 Authentication: MAC Similar to HMAC (uses concatenation instead of EXOR) Hash(MAC_secret_key pad2 hash(mac_secret_key pad1 seqnum SSLcompressed.type SSLcompressed.length SSLcompressed.fragment)) pad1=0x36 repeated 48 times (MD5); 40 times (SHA-1) pad2=0x5c repeated SSLcompressed.type = high level protocol used to process segment 28

29 encoding methods segment into blocks of 2 14 = bytes compression (optional): must be no lossy and must guarantee to reduce pack size default in SSLv3 : no compression MAC computation (see previous slide) on compressed data several (symmetric) encryption methods: block ciphers: IDEA (128) RC2-40, DES-40, DES (56), 3DES (168), Stream Cipher: RC4-40, RC4-128 Smart card: Fortezza 29

30 SSL - record fields of the header 30

31 fields Content Type (8 bits) The higher layer protocol used to process the enclosed fragment (change_cipher_spec, alert, handshake, and application_data. The first three are the SSL-specific protocols; no distinction is made among the various applications (e.g., HTTP) that might use SSL) Major Version (8 bits) Indicates major version of SSL in use. For SSLv3, the value is 3 Minor Version (8 bits) Indicates minor version in use. For SSLv3, the value is O Compressed Length (16 bits) The length in bytes of the plaintext fragment (or compressed fragment if compression is used). 31

32 SSL - Payload 32

33 SSL Change Cipher Spec Protocol one of 3 SSL specific protocols which use the SSL Record protocol a single message to cause the pending state to be copied into the current state, which updates the cipher suite to be used on this connection usually sent just after handshaking 33

34 SSL Alert Protocol conveys SSL-related alerts to peer entity severity two possibilities: warning or fatal (close connection) specific alert fatal: unexpected message, bad record mac, decompression failure, handshake failure, illegal parameter warning: close notify, no certificate, bad certificate, unsupported certificate, certificate revoked, certificate expired, certificate unknown compressed & encrypted like all SSL data 34

35 SSL Handshake Protocol Most complex part of SSL allows server & client to: authenticate each other to negotiate encryption & MAC algorithms to negotiate cryptographic keys to be used comprises a series of messages in phases Establish Security Capabilities Server Authentication and Key Exchange Client Authentication and Key Exchange Finish 35

36 SSL Handshake Protocol 36

37 Handshake protocol 4 steps 1. Hello: determine security capabilities 2. Server sends certificate, asks for certificate and starts exchange session keys 3. Client sends certificate and continues exchanges of keys 4. End of handshake protocol: encoded methods changes Note: some requests are optional clear separation between handshake and the rest (to avoid attacks) 37

38 Handshake: parameters message type Hello-request Client-hello Server_hello Certificate Server_key_exchange Certificate_request Server_done Certificate_verify Client_key_exchange Finished null parameters version, 32-bit timestamp + 28 random bytes (nonce, i.e. number used once), sessionid, cipher suite and compression method <same as Client_hello> X.509v3 chain of certificates info, signature of mess. type of cert., authority null signature of certificate info, signature of mess. hash of all exchanged messages (integrity of handshake CNS & protocol) SiReSI 38

39 Handshake Protocol - step 1 Initialization : Client_hello: client to server Version = highest SSL version used by client 32-bit timestamp + 28 bytes random (a pseudo number generator is required) sessionid: = 0 new connection in new session; 0 update previous connection Cipher suite: list that contains the combinations of cryptographic algorithms supported by the client, in decreasing order of preference. Each element of the list (each cipher suite) defines both a key exchange algorithm and a CipherSpec. Compression algorithms: ordered sequence of acceptable algorithms : Server_hello: server to client ack all above (if sessionid of client = 0 generates new sessionid) 39

40 Cipher suite Algorithms for key exchange RSA : session key is encoded with server public key Diffie-Hellman (several versions) Fixed Ephemeral Anonymous Fortezza CipherSpec Crypto algorithm (either a stream algo or a block algo) MAC algorithm Hash (in byte): 0, 16 (for MD5), 20 (for SHA-1) Key material info used to generate session keys Info for initializing CBC (initial vector) 40

41 Fixed Diffie-Hellman Diffie-Hellman key exchange in which server's certificate contains Diffie-Hellman public parameters signed by the certificate authority (CA). Client provides its Diffie-Hellman public key parameters either in a certificate, if client authentication is required, or in a key exchange message. This method results in a fixed secret key between two peers, based on the Diffie- Hellman calculation using the fixed public keys. 41

42 Ephemeral Diffie-Hellman Used to create ephemeral (temporary, onetime) secret keys. In this case, the Diffie- Hellman public keys are exchanged, signed using the sender's private RSA or DSS key. The receiver can use the corresponding public key to verify the signature. Certificates are used to authenticate the public keys. This would appear to be the most secure of the three Diffie-Hellman options because it results in a temporary, authenticated key. 42

43 Anonymous Diffie-Hellman The base Diffie-Hellman algorithm is used, with no authentication. Each side sends its public Diffie- Hellman parameters to the other, with no authentication. This approach is vulnerable to man-in-the-middle attacks, in which the attacker conducts anonymous Diffie-Hellman with both parties. 43

44 Handshake Protocol - step 2 Server authentication and key exchange Server to client Certificate: X.509 certificate chain (optional) Server_key_exchange (optional) a signature is created by taking the hash of a message and encrypting it with the sender's private key. In this case the hash is defined as hash(clienthello.random ServerHello.random ServerParams) So the hash covers also the two nonces from the initial hello messages. Certificate_request: (optional) Server_hello_done: I am done and I wait for answers 44

45 Certificate message The server begins this phase by sending its certificate, if it needs to be authenticated; the message contains one or a chain of X.509 certificates. The certificate message is required for any agreed-on key exchange method except anonymous Diffie-Hellman. If fixed Diffie-Hellman is used, this certificate message functions as the server's key exchange message because it contains the server's public Diffie- Hellman parameters. 45

46 server_key_exchange not needed A server_key_exchange message is not required in two instances: (1) The server has sent a certificate with fixed Diffie-Hellman parameters, or (2) RSA key exchange is to be used. 46

47 server_key_exchange needed Anonymous Diffie-Hellman. Message content consists of the two global D.H. values (a prime number and a primitive root of that number) plus the server's public D.H. key Ephemeral Diffie-Hellman. Message content includes the three D.H. parameters provided for anonymous D.H. plus a signature of those parameters. RSA key exchange, in which the server is using RSA but has a signature-only RSA key. Server creates a temporary RSA public/private key pair and use server_key_exchange message to send public key. Message content includes the two parameters of the temporary RSA public key (exponent and modulus) plus a signature of those parameters. 47

48 Handshake Protocol - step 3 Client authentication Client verifies server certificates and parameters Client to server Client Certificate and info to verify it: (if asked) Message for key exchange (Client_key_exchange) 48

49 Handshake Protocol - step 4 End: go to next phase, cipher_spec Client to server Message: Change_cipher_spec Finished message under new algorithms, keys (new cipher_spec) Server sends back Message: Change_cipher_spec Finished message under new algorithms, keys (new cipher_spec) 49

50 SSL & TLS IETF standard RFC 2246 similar to SSLv3 with minor differences in record format version number uses HMAC for MAC a pseudo-random function expands secrets has additional alert codes some changes in supported ciphers changes in certificate negotiations changes in use of padding 50

51 Paying in the Web: SSL SSL and credit card are used for paying simple no need of specialized software compliant with credit card mechanisms most used method for paying in the web Problems malicious sellers have info on clients clients can in principle refuse to pay (there is no signature) many disputes (20%- 60%) expensive method for the shop 51

52 Secure Electronic Transactions (SET) open encryption & security specification to protect Internet credit card transactions developed in 1996 by Mastercard, Visa etc not a payment system rather a set of security protocols & formats secure communications amongst parties trust from use of X.509v3 certificates privacy by restricted info to those who need it 52

53 components 1 Cardholder: Purchasers interact with merchants from personal computers over the Internet. A cardholder is an authorized holder of a payment card (e.g., MasterCard, Visa) that has been issued by an issuer. Merchant: Person/organization that has goods or services to sell to cardholders, offered via a Web site or by electronic mail. A merchant that accepts payment cards must have a relationship with an acquirer. 53

54 components 2 Issuer: Financial institution that provides the cardholder with the payment card. Ultimately, it is the issuer that is responsible for the payment of the debt of the cardholder. Acquirer: Financial institution that establishes an account with a merchant and processes authorizations (card account must be active and proposed purchase does not exceed credit limit) and payments (electronic transfer of payments to merchant's account). Subsequently, acquirer is reimbursed by issuer over some sort of payment network for electronic funds transfer. 54

55 components 3 Payment gateway: Function operated by acquirer or a designated third party that processes merchant payment messages. It interfaces between SET and the existing bankcard payment networks for authorization and payment functions. The merchant exchanges SET messages with the payment gateway over the Internet, while the payment gateway has some direct or network connection to the acquirer's financial processing system. Certification authority (CA): Entity that is trusted to issue X.509v3 public-key certificates for cardholders, merchants and payment gateways. A hierarchy of CAs is used, so that participants need not be directly certified by a root authority. 55

56 SET Components 56

57 SET Transaction 1. customer opens account 2. customer receives a certificate 3. merchants have their own certificates 4. customer places an order 5. merchant is verified 6. order and payment are sent 7. merchant requests payment authorization 8. merchant confirms order 9. merchant provides goods or service 10.merchant requests payment 57

58 transactions 1 1. The customer opens an account. Customer obtains credit card account (e.g., MasterCard or Visa) with a bank that supports electronic payment and SET. 2. The customer receives a certificate. After suitable verification of identity, customer receives an X509v3 digital certificate, signed by the bank. Certificate verifies the customer's RSA public key and its expiration date. It also establishes a relationship, guaranteed by the bank, between customer's key pair and credit card. 58

59 transactions 2 3. Merchants have their own certificates. Merchant accepting a brand of card must be in possession of two certificates for two public keys owned by the merchant: one for signing messages, and one for key exchange. The merchant also needs a copy of the payment gateway's public-key certificate. 4. Customer places order. Customer (possibly) browses through merchant's Web site to select items and see prices. Customer then sends list of items to be purchased to the merchant, who returns an order form containing the list of items, their price, a total price, and an order number. 59

60 transactions 3 5. Merchant is verified. Merchant also sends a copy of its certificate, so that customer can verify about dealing with a valid store. 6. Order and payment are sent. Customer sends both order and payment information to merchant, along with certificate. Order confirms the purchase of the items in the order form. Payment contains credit card details. Payment information is encrypted and cannot be read by merchant. 7. Merchant requests payment authorization. Merchant sends payment information to payment gateway, requesting authorization. 60

61 transactions 4 8. Merchant confirms the order. Merchant sends confirmation of the order to customer. 9. Merchant provides the goods or service. Merchant ships the goods or provides the service to customer. 10.Merchant requests payment. Request is sent to the payment gateway, which handles all of the payment processing. 61

62 Dual Signature customer creates dual messages order information (OI) for merchant payment information (PI) for bank neither party needs details of other but must know they are linked use a dual signature for this signed concatenated hashes of OI & PI 62

63 dual signature schema 63

64 SET transaction types 1/4 transaction type Cardholder registration Merchant registration Purchase request Payment authorization Payment capture info Cardholders must register with a CA before they can send SET messages to merchants. Merchants must register with a CA before they can exchange SET messages with customers and payment gateways. Message from customer to merchant containing OI for merchant and PI for bank. Exchange between merchant and payment gateway to authorize a given amount for a purchase on a given credit card account. Allows the merchant to request payment from the payment gateway. 64

65 SET transaction types 2/4 transaction type Certificate inquiry and status Purchase inquiry info If the CA is unable to complete the processing of a certificate request quickly, it will send a reply to the cardholder or merchant indicating that the requester should check back later. The cardholder or merchant sends the Certificate Inquiry message to determine the status of the certificate request and to receive the certificate if the request has been approved. Allows the cardholder to check the status of the processing of an order after the purchase response has been received. Note that this message does not include information such as the status of backordered goods but does indicate the status of authorization, capture, and credit processing. 65

66 SET transaction types 3/4 transaction type Authorization reversal Capture reversal Credit info Allows a merchant to correct previous authorization requests. If the order will not be completed, the merchant reverses the entire authorization. If part of the order will not be completed, the merchant reverses part of the amount of the authorization. Allows a merchant to correct errors in capture requests such as transaction amounts that were entered incorrectly by a clerk. Allows a merchant to issue a credit to a cardholder's account such as when goods are returned or were damaged during shipping. Note that the SET Credit message is airways initiated by the merchant, not the cardholder. All communications between the cardholder and merchant that result in a credit being processed happen outside of SET. 66

67 SET transaction types 4/4 transaction type Credit reversal Payment gateway request Batch administration Error message info Allows a merchant to correct a previously request credit. Allows a merchant to query the payment gateway and receive a copy of the gateway's current key exchange and signature certificates. Allows a merchant to communicate information to the payment gateway regarding merchant batches. Indicates that a responder rejects a message because it fails format or content verification tests. 67

68 Purchase Request Customer needed for verification merchant doesn t know K S generated by customer 68

69 Purchase Request Merchant 69

70 Purchase Request Merchant 1. verifies cardholder certificates using CA sigs 2. verifies dual signature using customer's public signature key to ensure order has not been tampered with in transit & that it was signed using cardholder's private signature key 3. processes order and forwards the payment information to the payment gateway for authorization (see next) 4. sends a purchase response to cardholder 70

71 Payment Gateway Authorization 1. verifies all certificates 2. decrypts digital envelope of authorization block to obtain symmetric key & then decrypts authorization block 3. verifies merchant's signature on authorization block 4. decrypts digital envelope of payment block to obtain symmetric key & then decrypts payment block 5. verifies dual signature on payment block 6. verifies that transaction ID received from merchant matches that in PI received (indirectly) from customer 7. requests & receives an authorization from issuer 8. sends authorization response back to merchant 71

72 Payment Capture merchant sends payment gateway a payment capture request gateway checks request then causes funds to be transferred to merchants account notifies merchant using capture response 72

Communication Systems SSL

Communication Systems SSL Communication Systems SSL Computer Science Organization I. Data and voice communication in IP networks II. Security issues in networking III. Digital telephony networks and voice over IP 2 Network Security

More information

Communication Systems 16 th lecture. Chair of Communication Systems Department of Applied Sciences University of Freiburg 2009

Communication Systems 16 th lecture. Chair of Communication Systems Department of Applied Sciences University of Freiburg 2009 16 th lecture Chair of Communication Systems Department of Applied Sciences University of Freiburg 2009 1 25 Organization Welcome to the New Year! Reminder: Structure of Communication Systems lectures

More information

Real-Time Communication Security: SSL/TLS. Guevara Noubir noubir@ccs.neu.edu CSU610

Real-Time Communication Security: SSL/TLS. Guevara Noubir noubir@ccs.neu.edu CSU610 Real-Time Communication Security: SSL/TLS Guevara Noubir noubir@ccs.neu.edu CSU610 1 Some Issues with Real-time Communication Session key establishment Perfect Forward Secrecy Diffie-Hellman based PFS

More information

Web Security Considerations

Web Security Considerations CEN 448 Security and Internet Protocols Chapter 17 Web Security Dr. Mostafa Hassan Dahshan Computer Engineering Department College of Computer and Information Sciences King Saud University mdahshan@ccis.ksu.edu.sa

More information

Cryptography and Network Security IPSEC

Cryptography and Network Security IPSEC Cryptography and Network Security IPSEC Security architecture and protocol stack Applicaz. (SHTTP) SSL/TLS TCP IPSEC IP Secure applications: PGP, SHTTP, SFTP, or Security down in the protocol stack -SSL

More information

Communication Security for Applications

Communication Security for Applications Communication Security for Applications Antonio Carzaniga Faculty of Informatics University of Lugano March 10, 2008 c 2008 Antonio Carzaniga 1 Intro to distributed computing: -server computing Transport-layer

More information

Secure Socket Layer/ Transport Layer Security (SSL/TLS)

Secure Socket Layer/ Transport Layer Security (SSL/TLS) Secure Socket Layer/ Transport Layer Security (SSL/TLS) David Sánchez Universitat Pompeu Fabra World Wide Web (www) Client/server services running over the Internet or TCP/IP Intranets nets widely used

More information

Chapter 17. Transport-Level Security

Chapter 17. Transport-Level Security Chapter 17 Transport-Level Security Web Security Considerations The World Wide Web is fundamentally a client/server application running over the Internet and TCP/IP intranets The following characteristics

More information

Secure Socket Layer. Security Threat Classifications

Secure Socket Layer. Security Threat Classifications Secure Socket Layer 1 Security Threat Classifications One way to classify Web security threats in terms of the type of the threat: Passive threats Active threats Another way to classify Web security threats

More information

CSC 474 Information Systems Security

CSC 474 Information Systems Security CSC 474 Information Systems Security Topic 4.5 Transport Layer Security CSC 474 Dr. Peng Ning 1 Transport Layer Security Protocols Secure Socket Layer (SSL) Originally developed to secure http Version

More information

CSC 774 -- Network Security

CSC 774 -- Network Security CSC 774 -- Network Security Topic 6: Transport Layer Security Dr. Peng Ning CSC 774 Network Security 1 Transport Layer Security Protocols Secure Socket Layer (SSL) Originally developed to secure http Version

More information

Network Security Essentials Chapter 5

Network Security Essentials Chapter 5 Network Security Essentials Chapter 5 Fourth Edition by William Stallings Lecture slides by Lawrie Brown Chapter 5 Transport-Level Security Use your mentality Wake up to reality From the song, "I've Got

More information

Managing and Securing Computer Networks. Guy Leduc. Chapter 4: Securing TCP. connections. connections. Chapter goals: security in practice:

Managing and Securing Computer Networks. Guy Leduc. Chapter 4: Securing TCP. connections. connections. Chapter goals: security in practice: Managing and Securing Computer Networks Guy Leduc Chapter 4: Securing TCP connections Computer Networking: A Top Down Approach, 6 th edition. Jim Kurose, Keith Ross Addison-Wesley, March 2012. (section

More information

SSL Secure Socket Layer

SSL Secure Socket Layer ??? SSL Secure Socket Layer - architecture and services - sessions and connections - SSL Record Protocol - SSL Handshake Protocol - key exchange alternatives - analysis of the SSL Record and Handshake

More information

Chapter 7 Transport-Level Security

Chapter 7 Transport-Level Security Cryptography and Network Security Chapter 7 Transport-Level Security Lectured by Nguyễn Đức Thái Outline Web Security Issues Security Socket Layer (SSL) Transport Layer Security (TLS) HTTPS Secure Shell

More information

SECURE SOCKETS LAYER (SSL)

SECURE SOCKETS LAYER (SSL) INFS 766 Internet Security Protocols Lecture 5 SSL Prof. Ravi Sandhu SECURE SOCKETS LAYER (SSL) layered on top of TCP SSL versions 1.0, 2.0, 3.0, 3.1 Netscape protocol later refitted as IETF standard TLS

More information

CS 356 Lecture 27 Internet Security Protocols. Spring 2013

CS 356 Lecture 27 Internet Security Protocols. Spring 2013 CS 356 Lecture 27 Internet Security Protocols Spring 2013 Review Chapter 1: Basic Concepts and Terminology Chapter 2: Basic Cryptographic Tools Chapter 3 User Authentication Chapter 4 Access Control Lists

More information

Secure Sockets Layer

Secure Sockets Layer SSL/TLS provides endpoint authentication and communications privacy over the Internet using cryptography. For web browsing, email, faxing, other data transmission. In typical use, only the server is authenticated

More information

WEB Security: Secure Socket Layer

WEB Security: Secure Socket Layer WEB Security: Secure Socket Layer Cunsheng Ding HKUST, Hong Kong, CHINA C. Ding - COMP581 - L22 1 Outline of this Lecture Brief Information on SSL and TLS Secure Socket Layer (SSL) Transport Layer Security

More information

Transport Level Security

Transport Level Security Transport Level Security Overview Raj Jain Washington University in Saint Louis Saint Louis, MO 63130 Jain@cse.wustl.edu Audio/Video recordings of this lecture are available at: http://www.cse.wustl.edu/~jain/cse571-14/

More information

Transport Layer Security Protocols

Transport Layer Security Protocols SSL/TLS 1 Transport Layer Security Protocols Secure Socket Layer (SSL) Originally designed to by Netscape to secure HTTP Version 2 is being replaced by version 3 Subsequently became Internet Standard known

More information

Announcement. Final exam: Wed, June 9, 9:30-11:18 Scope: materials after RSA (but you need to know RSA) Open books, open notes. Calculators allowed.

Announcement. Final exam: Wed, June 9, 9:30-11:18 Scope: materials after RSA (but you need to know RSA) Open books, open notes. Calculators allowed. Announcement Final exam: Wed, June 9, 9:30-11:18 Scope: materials after RSA (but you need to know RSA) Open books, open notes. Calculators allowed. 1 We have learned Symmetric encryption: DES, 3DES, AES,

More information

The Secure Sockets Layer (SSL)

The Secure Sockets Layer (SSL) Due to the fact that nearly all businesses have websites (as well as government agencies and individuals) a large enthusiasm exists for setting up facilities on the Web for electronic commerce. Of course

More information

Outline. Transport Layer Security (TLS) Security Protocols (bmevihim132)

Outline. Transport Layer Security (TLS) Security Protocols (bmevihim132) Security Protocols (bmevihim132) Dr. Levente Buttyán associate professor BME Híradástechnikai Tanszék Lab of Cryptography and System Security (CrySyS) buttyan@hit.bme.hu, buttyan@crysys.hu Outline - architecture

More information

Security Protocols and Infrastructures. h_da, Winter Term 2011/2012

Security Protocols and Infrastructures. h_da, Winter Term 2011/2012 Winter Term 2011/2012 Chapter 7: Transport Layer Security Protocol Key Questions Application context of TLS? Which security goals shall be achieved? Approaches? 2 Contents Overview Record Protocol Cipher

More information

Security Engineering Part III Network Security. Security Protocols (I): SSL/TLS

Security Engineering Part III Network Security. Security Protocols (I): SSL/TLS Security Engineering Part III Network Security Security Protocols (I): SSL/TLS Juan E. Tapiador jestevez@inf.uc3m.es Department of Computer Science, UC3M Security Engineering 4th year BSc in Computer Science,

More information

Authentication applications Kerberos X.509 Authentication services E mail security IP security Web security

Authentication applications Kerberos X.509 Authentication services E mail security IP security Web security UNIT 4 SECURITY PRACTICE Authentication applications Kerberos X.509 Authentication services E mail security IP security Web security Slides Courtesy of William Stallings, Cryptography & Network Security,

More information

Secure Socket Layer (SSL) and Transport Layer Security (TLS)

Secure Socket Layer (SSL) and Transport Layer Security (TLS) Secure Socket Layer (SSL) and Transport Layer Security (TLS) Raj Jain Washington University in Saint Louis Saint Louis, MO 63130 Jain@cse.wustl.edu Audio/Video recordings of this lecture are available

More information

SSL Secure Socket Layer

SSL Secure Socket Layer ??? SSL Secure Socket Layer - architecture and services - sessions and connections - SSL Record Protocol - SSL Handshake Protocol - key exchange alternatives - analysis of the SSL Record and Handshake

More information

Overview of CSS SSL. SSL Cryptography Overview CHAPTER

Overview of CSS SSL. SSL Cryptography Overview CHAPTER CHAPTER 1 Secure Sockets Layer (SSL) is an application-level protocol that provides encryption technology for the Internet, ensuring secure transactions such as the transmission of credit card numbers

More information

ECE-8843 Prof. John A. Copeland 404 894-5177 fax 404 894-0035

ECE-8843  Prof. John A. Copeland 404 894-5177 fax 404 894-0035 ECE-8843 http://www.csc.gatech.edu/copeland/jac/8813-03/ Prof. John A. Copeland john.copeland@ece.gatech.edu 404 894-5177 fax 404 894-0035 Office: GCATT Bldg 579 email or call for office visit, or call

More information

Network Security Web Security and SSL/TLS. Angelos Keromytis Columbia University

Network Security Web Security and SSL/TLS. Angelos Keromytis Columbia University Network Security Web Security and SSL/TLS Angelos Keromytis Columbia University Web security issues Authentication (basic, digest) Cookies Access control via network address Multiple layers SHTTP SSL (TLS)

More information

Overview. SSL Cryptography Overview CHAPTER 1

Overview. SSL Cryptography Overview CHAPTER 1 CHAPTER 1 Note The information in this chapter applies to both the ACE module and the ACE appliance unless otherwise noted. The features in this chapter apply to IPv4 and IPv6 unless otherwise noted. Secure

More information

Web Security. Introduction: Understand applicable laws, legal issues and ethical issues regarding computer crime

Web Security. Introduction: Understand applicable laws, legal issues and ethical issues regarding computer crime International Journal for Science and Emerging ISSN No. (Online):2250-3641 Technologies with Latest Trends 12(1): 1-6 (2013) ISSN No. (Print): 2277-8136 Web Security Amandeep Kang*, Navdeep Kaholn** and

More information

Network Security Part II: Standards

Network Security Part II: Standards Network Security Part II: Standards Raj Jain Washington University Saint Louis, MO 63131 Jain@cse.wustl.edu These slides are available on-line at: http://www.cse.wustl.edu/~jain/cse473-05/ 18-1 Overview

More information

SECURE SOCKETS LAYER (SSL) SECURE SOCKETS LAYER (SSL) SSL ARCHITECTURE SSL/TLS DIFFERENCES SSL ARCHITECTURE. INFS 766 Internet Security Protocols

SECURE SOCKETS LAYER (SSL) SECURE SOCKETS LAYER (SSL) SSL ARCHITECTURE SSL/TLS DIFFERENCES SSL ARCHITECTURE. INFS 766 Internet Security Protocols INFS 766 Internet Security s Lecture 5 SSL Prof. Ravi Sandhu SECURE SOCKETS LAYER (SSL) layered on top of TCP SSL versions 1.0, 2.0, 3.0, 3.1 Netscape protocol later refitted as IETF standard TLS (Transport

More information

Secure Sockets Layer (SSL ) / Transport Layer Security (TLS) Network Security Products S31213

Secure Sockets Layer (SSL ) / Transport Layer Security (TLS) Network Security Products S31213 Secure Sockets Layer (SSL ) / Transport Layer Security (TLS) Network Security Products S31213 UNCLASSIFIED Example http ://www. greatstuf f. com Wants credit card number ^ Look at lock on browser Use https

More information

WEB Security & SET. Outline. Web Security Considerations. Web Security Considerations. Secure Socket Layer (SSL) and Transport Layer Security (TLS)

WEB Security & SET. Outline. Web Security Considerations. Web Security Considerations. Secure Socket Layer (SSL) and Transport Layer Security (TLS) Outline WEB Security & SET (Chapter 19 & Stalling Chapter 7) Web Security Considerations Secure Socket Layer (SSL) and Transport Layer Security (TLS) Secure Electronic Transaction (SET) Web Security Considerations

More information

Web Security. Mahalingam Ramkumar

Web Security. Mahalingam Ramkumar Web Security Mahalingam Ramkumar Issues Phishing Spreading misinformation Cookies! Authentication Domain name DNS Security Transport layer security Dynamic HTML Java applets, ActiveX, JavaScript Exploiting

More information

Secure Socket Layer (SSL) and Trnasport Layer Security (TLS)

Secure Socket Layer (SSL) and Trnasport Layer Security (TLS) Secure Socket Layer (SSL) and Trnasport Layer Security (TLS) CSE598K/CSE545 - Advanced Network Security Prof. McDaniel - Spring 2008 1 SSL/TLS The Secure Socket Layer (SSL) and Transport Layer Security

More information

Network Security - Secure upper layer protocols - Background. Email Security. Question from last lecture: What s a birthday attack? Dr.

Network Security - Secure upper layer protocols - Background. Email Security. Question from last lecture: What s a birthday attack? Dr. Network Security - Secure upper layer protocols - Dr. John Keeney 3BA33 Question from last lecture: What s a birthday attack? might think a m-bit hash is secure but by Birthday Paradox is not the chance

More information

Security. Contents. S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 1

Security. Contents. S-72.3240 Wireless Personal, Local, Metropolitan, and Wide Area Networks 1 Contents Security requirements Public key cryptography Key agreement/transport schemes Man-in-the-middle attack vulnerability Encryption. digital signature, hash, certification Complete security solutions

More information

, ) I Transport Layer Security

, ) I Transport Layer Security Secure Sockets Layer (SSL, ) I Transport Layer Security _ + (TLS) Network Security Products S31213 UNCLASSIFIED Location of SSL -L Protocols TCP Ethernet IP SSL Header Encrypted SSL data= HTTP " Independent

More information

Authenticity of Public Keys

Authenticity of Public Keys SSL/TLS EJ Jung 10/18/10 Authenticity of Public Keys Bob s key? private key Bob public key Problem: How does know that the public key she received is really Bob s public key? Distribution of Public Keys!

More information

3.2: Transport Layer: SSL/TLS Secure Socket Layer (SSL) Transport Layer Security (TLS) Protocol

3.2: Transport Layer: SSL/TLS Secure Socket Layer (SSL) Transport Layer Security (TLS) Protocol Chapter 2: Security Techniques Background Chapter 3: Security on Network and Transport Layer Network Layer: IPSec Transport Layer: SSL/TLS Chapter 4: Security on the Application Layer Chapter 5: Security

More information

Information Security

Information Security SE 4472 / ECE 9064 Information Security Week 11: Transport Layer Security (TLS): Putting it all together Fall 2015 Prof. Aleksander Essex Security at the Transport Layer Where we started in this course:

More information

Secure Socket Layer. Carlo U. Nicola, SGI FHNW With extracts from publications of : William Stallings.

Secure Socket Layer. Carlo U. Nicola, SGI FHNW With extracts from publications of : William Stallings. Secure Socket Layer Carlo U. Nicola, SGI FHNW With extracts from publications of : William Stallings. Abstraction: Crypto building blocks NS HS13 2 Abstraction: The secure channel 1., run a key-exchange

More information

Overview of SSL. Outline. CSC/ECE 574 Computer and Network Security. Reminder: What Layer? Protocols. SSL Architecture

Overview of SSL. Outline. CSC/ECE 574 Computer and Network Security. Reminder: What Layer? Protocols. SSL Architecture OS Appl. CSC/ECE 574 Computer and Network Security Outline I. Overview II. The Record Protocol III. The Handshake and Other Protocols Topic 8.3 /TLS 1 2 Reminder: What Layer? Overview of 3 4 Protocols

More information

Network Security [2] Plain text Encryption algorithm Public and private key pair Cipher text Decryption algorithm. See next slide

Network Security [2] Plain text Encryption algorithm Public and private key pair Cipher text Decryption algorithm. See next slide Network Security [2] Public Key Encryption Also used in message authentication & key distribution Based on mathematical algorithms, not only on operations over bit patterns (as conventional) => much overhead

More information

HTTPS: Transport-Layer Security (TLS), aka Secure Sockets Layer (SSL)

HTTPS: Transport-Layer Security (TLS), aka Secure Sockets Layer (SSL) CSCD27 Computer and Network Security HTTPS: Transport-Layer Security (TLS), aka Secure Sockets Layer (SSL) 11 SSL CSCD27 Computer and Network Security 1 CSCD27F Computer and Network Security 1 TLS (Transport-Layer

More information

Overview. SSL Cryptography Overview CHAPTER 1

Overview. SSL Cryptography Overview CHAPTER 1 CHAPTER 1 Secure Sockets Layer (SSL) is an application-layer protocol that provides encryption technology for the Internet. SSL ensures the secure transmission of data between a client and a server through

More information

Secure Socket Layer (TLS) Carlo U. Nicola, SGI FHNW With extracts from publications of : William Stallings.

Secure Socket Layer (TLS) Carlo U. Nicola, SGI FHNW With extracts from publications of : William Stallings. Secure Socket Layer (TLS) Carlo U. Nicola, SGI FHNW With extracts from publications of : William Stallings. Crypto building blocks AS HS13 2 Abstraction: The secure channel 1., run a key-exchange protocol

More information

Savitribai Phule Pune University

Savitribai Phule Pune University Savitribai Phule Pune University Centre for Information and Network Security Course: Introduction to Cyber Security / Information Security Module : Pre-requisites in Information and Network Security Chapter

More information

Security Protocols HTTPS/ DNSSEC TLS. Internet (IPSEC) Network (802.1x) Application (HTTP,DNS) Transport (TCP/UDP) Transport (TCP/UDP) Internet (IP)

Security Protocols HTTPS/ DNSSEC TLS. Internet (IPSEC) Network (802.1x) Application (HTTP,DNS) Transport (TCP/UDP) Transport (TCP/UDP) Internet (IP) Security Protocols Security Protocols Necessary to communicate securely across untrusted network Provide integrity, confidentiality, authenticity of communications Based on previously discussed cryptographic

More information

Protocol Rollback and Network Security

Protocol Rollback and Network Security CSE 484 / CSE M 584 (Spring 2012) Protocol Rollback and Network Security Tadayoshi Kohno Thanks to Dan Boneh, Dieter Gollmann, Dan Halperin, John Manferdelli, John Mitchell, Vitaly Shmatikov, Bennet Yee,

More information

Payment authorization Payment capture Table 1.3 SET Transaction Types

Payment authorization Payment capture Table 1.3 SET Transaction Types Table 1.3 lists the transaction types supported by SET. In what follows we look in some detail at the following transactions: Purchase request Payment authorization Payment capture Cardholder registration

More information

Lecture 4: Transport Layer Security (secure Socket Layer)

Lecture 4: Transport Layer Security (secure Socket Layer) Lecture 4: Transport Layer Security (secure Socket Layer) Recommended reading: Thomas, SSS and TLS essentials (old but very well written) SSL/TLS: layered view HTTP SMTP TCP/UDP IPsec Network layer security

More information

Part III-b. Universität Klagenfurt - IWAS Multimedia Kommunikation (VK) M. Euchner; Mai 2001. Siemens AG 2001, ICN M NT

Part III-b. Universität Klagenfurt - IWAS Multimedia Kommunikation (VK) M. Euchner; Mai 2001. Siemens AG 2001, ICN M NT Part III-b Contents Part III-b Secure Applications and Security Protocols Practical Security Measures Internet Security IPSEC, IKE SSL/TLS Virtual Private Networks Firewall Kerberos SET Security Measures

More information

Security Protocols/Standards

Security Protocols/Standards Security Protocols/Standards Security Protocols/Standards Security Protocols/Standards How do we actually communicate securely across a hostile network? Provide integrity, confidentiality, authenticity

More information

Lecture 7: Transport Level Security SSL/TLS. Course Admin

Lecture 7: Transport Level Security SSL/TLS. Course Admin Lecture 7: Transport Level Security SSL/TLS CS 336/536: Computer Network Security Fall 2014 Nitesh Saxena Adopted from previous lecture by Tony Barnard Course Admin HW/Lab 1 Graded; scores posted; to be

More information

INF3510 Information Security University of Oslo Spring 2011. Lecture 9 Communication Security. Audun Jøsang

INF3510 Information Security University of Oslo Spring 2011. Lecture 9 Communication Security. Audun Jøsang INF3510 Information Security University of Oslo Spring 2011 Lecture 9 Communication Security Audun Jøsang Outline Network security concepts Communication security Perimeter security Protocol architecture

More information

ISA 562 Information System Security

ISA 562 Information System Security Outline ISA 562 Information System Security PKI SSL PKI SSL ISA 562 1 ISA 562 2 Motivation 1- Key Distribution Problem In a secret key cryptosystem, the secret key must be transmitted via a secure channel

More information

Security. Learning Objectives. This module will help you...

Security. Learning Objectives. This module will help you... Security 5-1 Learning Objectives This module will help you... Understand the security infrastructure supported by JXTA Understand JXTA's use of TLS for end-to-end security 5-2 Highlights Desired security

More information

SSL/TLS. What Layer? History. SSL vs. IPsec. SSL Architecture. SSL Architecture. IT443 Network Security Administration Instructor: Bo Sheng

SSL/TLS. What Layer? History. SSL vs. IPsec. SSL Architecture. SSL Architecture. IT443 Network Security Administration Instructor: Bo Sheng What Layer? /TLS IT443 Network Security Administration Instructor: Bo Sheng Application TCP IPSec IP LAN layer Application TCP IP LAN layer 1 2 History v2 proposed and deployed in Netscape 1.1 (1995) PCT

More information

Web Security (SSL) Tecniche di Sicurezza dei Sistemi 1

Web Security (SSL) Tecniche di Sicurezza dei Sistemi 1 Web Security (SSL) Tecniche di Sicurezza dei Sistemi 1 How the Web Works - HTTP Hypertext transfer protocol (http). Clients request documents (or scripts) through URL. Server response with documents. Documents

More information

Software Engineering 4C03 Research Project. An Overview of Secure Transmission on the World Wide Web. Sean MacDonald 0043306

Software Engineering 4C03 Research Project. An Overview of Secure Transmission on the World Wide Web. Sean MacDonald 0043306 Software Engineering 4C03 Research Project An Overview of Secure Transmission on the World Wide Web Sean MacDonald 0043306 Tuesday April 5, 2005 Introduction Software Engineering 4C03 Research Project

More information

Three attacks in SSL protocol and their solutions

Three attacks in SSL protocol and their solutions Three attacks in SSL protocol and their solutions Hong lei Zhang Department of Computer Science The University of Auckland zhon003@ec.auckland.ac.nz Abstract Secure Socket Layer (SSL) and Transport Layer

More information

Bit Chat: A Peer-to-Peer Instant Messenger

Bit Chat: A Peer-to-Peer Instant Messenger Bit Chat: A Peer-to-Peer Instant Messenger Shreyas Zare shreyas@technitium.com https://technitium.com December 20, 2015 Abstract. Bit Chat is a peer-to-peer instant messaging concept, allowing one-to-one

More information

Computer and Network Security

Computer and Network Security Computer and Network Security c Copyright 2000 R E Newman Computer & Information Sciences & Engineering University Of Florida Gainesville, Florida 32611-6120 nemo@ciseufledu Network Security Protocols

More information

7 Network Security. 7.1 Introduction 7.2 Improving the Security 7.3 Internet Security Framework. 7.5 Absolute Security?

7 Network Security. 7.1 Introduction 7.2 Improving the Security 7.3 Internet Security Framework. 7.5 Absolute Security? 7 Network Security 7.1 Introduction 7.2 Improving the Security 7.3 Internet Security Framework 7.4 Firewalls 7.5 Absolute Security? 7.1 Introduction Security of Communications data transport e.g. risk

More information

Chapter 11 Security Protocols. Network Security Threats Security and Cryptography Network Security Protocols Cryptographic Algorithms

Chapter 11 Security Protocols. Network Security Threats Security and Cryptography Network Security Protocols Cryptographic Algorithms Chapter 11 Security Protocols Network Security Threats Security and Cryptography Network Security Protocols Cryptographic Algorithms Chapter 11 Security Protocols Network Security Threats Network Security

More information

Using etoken for SSL Web Authentication. SSL V3.0 Overview

Using etoken for SSL Web Authentication. SSL V3.0 Overview Using etoken for SSL Web Authentication Lesson 12 April 2004 etoken Certification Course SSL V3.0 Overview Secure Sockets Layer protocol, version 3.0 Provides communication privacy over the internet. Prevents

More information

Chapter 10. Network Security

Chapter 10. Network Security Chapter 10 Network Security 10.1. Chapter 10: Outline 10.1 INTRODUCTION 10.2 CONFIDENTIALITY 10.3 OTHER ASPECTS OF SECURITY 10.4 INTERNET SECURITY 10.5 FIREWALLS 10.2 Chapter 10: Objective We introduce

More information

TLS and SRTP for Skype Connect. Technical Datasheet

TLS and SRTP for Skype Connect. Technical Datasheet TLS and SRTP for Skype Connect Technical Datasheet Copyright Skype Limited 2011 Introducing TLS and SRTP Protocols help protect enterprise communications Skype Connect now provides Transport Layer Security

More information

Introduction to Cryptography

Introduction to Cryptography Introduction to Cryptography Part 3: real world applications Jean-Sébastien Coron January 2007 Public-key encryption BOB ALICE Insecure M E C C D channel M Alice s public-key Alice s private-key Authentication

More information

Lecture 31 SSL. SSL: Secure Socket Layer. History SSL SSL. Security April 13, 2005

Lecture 31 SSL. SSL: Secure Socket Layer. History SSL SSL. Security April 13, 2005 Lecture 31 Security April 13, 2005 Secure Sockets Layer (Netscape 1994) A Platform independent, application independent protocol to secure TCP based applications Currently the most popular internet crypto-protocol

More information

Secure Socket Layer. Introduction Overview of SSL What SSL is Useful For

Secure Socket Layer. Introduction Overview of SSL What SSL is Useful For Secure Socket Layer Secure Socket Layer Introduction Overview of SSL What SSL is Useful For Introduction Secure Socket Layer (SSL) Industry-standard method for protecting web communications. - Data encryption

More information

SSL and TLS. An Overview of A Secure Communications Protocol. Simon Horman aka Horms. horms@valinux.co.jp horms@verge.net.au horms@debian.

SSL and TLS. An Overview of A Secure Communications Protocol. Simon Horman aka Horms. horms@valinux.co.jp horms@verge.net.au horms@debian. SSL and TLS An Overview of A Secure Communications Protocol Simon Horman aka Horms horms@valinux.co.jp horms@verge.net.au horms@debian.org Presented at the Security Mini-Conf at Linux.Conf.Au Canberra,

More information

SSL: Secure Socket Layer

SSL: Secure Socket Layer SSL: Secure Socket Layer Steven M. Bellovin February 12, 2009 1 Choices in Key Exchange We have two basic ways to do key exchange, public key (with PKI or pki) or KDC Which is better? What are the properties

More information

Some solutions commonly used in order to guarantee a certain level of safety and security are:

Some solutions commonly used in order to guarantee a certain level of safety and security are: 1. SSL UNICAPT32 1.1 Introduction The following introduction contains large excerpts from the «TCP/IP Tutorial and Technical Overview IBM Redbook. Readers already familiar with SSL may directly go to section

More information

Overview SSL/TLS HTTPS SSH. TLS Protocol Architecture TLS Handshake Protocol TLS Record Protocol. SSH Protocol Architecture SSH Transport Protocol

Overview SSL/TLS HTTPS SSH. TLS Protocol Architecture TLS Handshake Protocol TLS Record Protocol. SSH Protocol Architecture SSH Transport Protocol SSL/TLS TLS Protocol Architecture TLS Handshake Protocol TLS Record Protocol HTTPS SSH SSH Protocol Architecture SSH Transport Protocol Overview SSH User Authentication Protocol SSH Connection Protocol

More information

SSL A discussion of the Secure Socket Layer

SSL A discussion of the Secure Socket Layer www.harmonysecurity.com info@harmonysecurity.com SSL A discussion of the Secure Socket Layer By Stephen Fewer Contents 1 Introduction 2 2 Encryption Techniques 3 3 Protocol Overview 3 3.1 The SSL Record

More information

TLS security protocol, Firewalls

TLS security protocol, Firewalls TLS security protocol, Firewalls Diana Berbecaru < diana.berbecaru @ polito.it > Politecnico di Torino Dip. Automatica e Informatica Security internal to the applications APP #1 sec... APP #N sec logical

More information

CS549: Cryptography and Network Security

CS549: Cryptography and Network Security CS549: Cryptography and Network Security by Xiang-Yang Li Department of Computer Science, IIT Cryptography and Network Security 1 Notice This lecture note (Cryptography and Network Security) is prepared

More information

Today s Topics SSL/TLS. Certification Authorities VPN. Server Certificates Client Certificates. Trust Registration Authorities

Today s Topics SSL/TLS. Certification Authorities VPN. Server Certificates Client Certificates. Trust Registration Authorities SSL/TLS Today s Topics Server Certificates Client Certificates Certification Authorities Trust Registration Authorities VPN IPSec Client tunnels LAN-to-LAN tunnels Secure Sockets Layer Secure Sockets Layer

More information

As enterprises conduct more and more

As enterprises conduct more and more Efficiently handling SSL transactions is one cornerstone of your IT security infrastructure. Do you know how the protocol actually works? Wesley Chou Inside SSL: The Secure Sockets Layer Protocol Inside

More information

IT Networks & Security CERT Luncheon Series: Cryptography

IT Networks & Security CERT Luncheon Series: Cryptography IT Networks & Security CERT Luncheon Series: Cryptography Presented by Addam Schroll, IT Security & Privacy Analyst 1 Outline History Terms & Definitions Symmetric and Asymmetric Algorithms Hashing PKI

More information

Institute of Computer Technology - Vienna University of Technology. L96 - SSL, PGP, Kerberos

Institute of Computer Technology - Vienna University of Technology. L96 - SSL, PGP, Kerberos SSL, PGP, Kerberos Secure Socket Layer (Web Security), Pretty Good Privacy (Email Security) and Authentication Agenda SSL PGP Kerberos SSL, PGP, Kerberos, v4.4 2 Page 96-1 SSL versus IPsec Application

More information

Learning Network Security with SSL The OpenSSL Way

Learning Network Security with SSL The OpenSSL Way Learning Network Security with SSL The OpenSSL Way Shalendra Chhabra schhabra@cs.ucr.edu. Computer Science and Enginering University of California, Riverside http://www.cs.ucr.edu/ schhabra Slides Available

More information

Lecture 13. Transport Layer Security/ Secure Socket Layer (TLS/SSL) (Chapter 9 in KPS)

Lecture 13. Transport Layer Security/ Secure Socket Layer (TLS/SSL) (Chapter 9 in KPS) Lecture 13 Transport Layer Security/ Secure Socket Layer (TLS/SSL) (Chapter 9 in KPS) SSL: Secure Sockets Layer vwidely deployed security protocol supported by almost all browsers, web servers the s in

More information

Transport Layer Security (TLS)

Transport Layer Security (TLS) Security Protocols (bmevihim132) Dr. Levente Buttyán associate professor BME Hálózati Rendszerek és Szolgáltatások Tanszék Lab of Cryptography and System Security (CrySyS) buttyan@hit.bme.hu, buttyan@crysys.hu

More information

Cryptography and Network Security

Cryptography and Network Security PART-A Questions 1. Name the aspects to be considered of information security. 2. What is meant by deciphering? 3. What are the two different uses of public key cryptography related to key distribution?

More information

CRYPTOGRAPHY IN NETWORK SECURITY

CRYPTOGRAPHY IN NETWORK SECURITY ELE548 Research Essays CRYPTOGRAPHY IN NETWORK SECURITY AUTHOR: SHENGLI LI INSTRUCTOR: DR. JIEN-CHUNG LO Date: March 5, 1999 Computer network brings lots of great benefits and convenience to us. We can

More information

Certificates and network security

Certificates and network security Certificates and network security Tuomas Aura CSE-C3400 Information security Aalto University, autumn 2014 Outline X.509 certificates and PKI Network security basics: threats and goals Secure socket layer

More information

SSL/TLS: The Ugly Truth

SSL/TLS: The Ugly Truth SSL/TLS: The Ugly Truth Examining the flaws in SSL/TLS protocols, and the use of certificate authorities. Adrian Hayter CNS Hut 3 Team adrian.hayter@cnsuk.co.uk Contents Introduction to SSL/TLS Cryptography

More information

SBClient SSL. Ehab AbuShmais

SBClient SSL. Ehab AbuShmais SBClient SSL Ehab AbuShmais Agenda SSL Background U2 SSL Support SBClient SSL 2 What Is SSL SSL (Secure Sockets Layer) Provides a secured channel between two communication endpoints Addresses all three

More information

T-79.159 Cryptography and Data Security

T-79.159 Cryptography and Data Security T-79.159 Cryptography and Data Security Lecture 11: Security systems using public keys 11.1 PGP Kaufman et al: Ch 17, 11.2 SSL/TLS 18, 19 11.3 IPSEC Stallings: Ch 16,17 1 Pretty Good Privacy Email encryption

More information

CS419: Computer Security

CS419: Computer Security CS419: Computer Security MAC, HMAC, Hash functions, DSA, SSL Vinod Ganapathy Message Authentication message authentication is concerned with: protecting the integrity of a message validating identity of

More information

Security for e-commerce

Security for e-commerce 11 Security for e-commerce Course Outline (tentative) 1. Basic Internet Concepts 2. HTML 3. XHTML 4. CSS (Style Sheets) 5. JavaScript (Client-Side Scripting) 6. XML and related technologies 7. WAP (Wireless

More information

EXAM questions for the course TTM4135 - Information Security May 2013. Part 1

EXAM questions for the course TTM4135 - Information Security May 2013. Part 1 EXAM questions for the course TTM4135 - Information Security May 2013 Part 1 This part consists of 5 questions all from one common topic. The number of maximal points for every correctly answered question

More information