TECHNOLOGY WHITEPAPER

Transcription

1 TECHNOLOGY WHITEPAPER ArmorVox10 Targets Call Center Fraud How to provide fast voice-file cross-matching to detect and track fraud in call centers. AURAYA SYSTEMS One Tara Boulevard Nashua, New Hampshire twitter.com/armorvox linkedin/in/armorvox

2 ArmorVox10 Targets Call Center Fraud Fraud on the Friendly Channel While banks and financial services companies have invested heavily (can we say over what period of time?) in technology to thwart phishing attacks and online fraud, call center and help desk security has been largely ignored. This has not gone unnoticed by the fraudsters who look for new opportunities to commit crimes and have increasingly turned their attention to the friendly channel the call center. To address the increasing threat posed by these socially engineered attacks and the misuse of stolen personal information, Auraya has developed ArmorVox10. ArmorVox10 is an advanced voice biometrics engine that provides language independent speaker verification and speaker identification functions. Based on Auraya s patented speaker adaptive technology, ArmorVox10 implements textdependent, text-independent and text-prompted verification functions, and also provides the fast voicefile cross-matching capability needed to detect and track fraud. For success in practical applications, systems must achieve high rates of cross-matching the ability to take a voice files from an unknown speaker and cross-match it with a database of known fraudsters to identify a mismatch. No other commercially available product conducts the level of cross-matching in the speed completed by ArmorVox10. Benchmarked at up to 3,000 voice file cross-matches per second on a single server, ArmorVox10 is arguably the fastest voice biometric engine on the market. It provides banks, government and financial service organizations with a potent new weapon in the battle against identity theft and fraud. Indeed, at these cross match speeds, real-time detection and tracking of fraudulent calls is now a viable proposition. 2

3 How ArmorVox Cross-Matching Works The ArmorVox10 cross-matching technology allows matching an utterance against a large number of stored voiceprints in real-time through the API of the ArmorVox server. This is useful in situations where an organization wishes to blacklist a number of users who try to enroll or verify into an existing voice authentication system. The operation is completed in real-time and in a covert fashion as part of the general authentication call where the utterance is authenticated or enrolled and is sent in parallel to the blacklist backend server. The utterance is cross-matched through an API call that is optimised for speed at the ArmorVox server end. The client request for cross-match is an HTTP that works by submitting an utterance to be crossmatched, as well as a list of speakers to be matched against. Thresholding is used to separate selfspeaker utterances from other utterances by using either a global threshold or following the speaker adaptive philosophy of the ArmorVox authentication technology individual speaker thresholds that are calculated by the system after the first successful verification. The server returns the number of matches against the enrolled users or zero if no match is found. At the client side, the processing can be done in three different ways: 1. Single-Threaded on a Single Server (Figure 1): The utterance and a list of enrolled users are sent through to the server for cross-matching. 2. Multi-Threaded on a Single Server (Figure 2-Red): In this case the list is sub-divided into N sets of size S and each set is submitted as a thread in parallel, thus taking advantage of the multithreaded nature of the ArmorVox server. The performance is thus dependent on the number of cores that are available on a particular hardware platform and the speed of these cores. 3. Multi-Threaded on Multiple Servers (Figure 2-RGB): This is similar to the previous case except that we now use several servers in parallel with each server doing the processing in a singlethreaded (1) or multi-threaded(2) mode. 3

4 Welcome to the ArmorVox Authentication System, please say your ID. One zero zero one one. I am sorry that ID cannot be verified. Goodbye. Landline LAN/WAN Thread1 VoicePrint 0 Speakers Mobile IVR/Communications Platform ArmorVox VoicePrint NxS Smartphone Figure 1 Cross-Matching: Single-Threaded API Call Thread1 VoicePrint 0 ArmorVox1 Welcome to the ArmorVox Authentication System, please say your ID. One zero zero one one. I am sorry that ID cannot be verified. Goodbye VoicePrint 1xS Landline VoicePrint (n-1)xs LAN/WAN Threadn Threadn Speakers Mobile IVR/Communications Platform ArmorVoxn VoicePrint nxs Smartphone ThreadN ThreadN VoicePrint (N-1)xS ArmorVoxN VoicePrint NxS 4

5 Figure 2 Cross-Matching: Multi-threaded API Calls to either Single Server (Red) or Multiple Servers (RGB). Description of the Experiments A number of experiments have been performed on servers having either an AMD Phenom II x6 or an Intel i7 quad-core with at least 8 GB of RAM: 1. 10,000 were enrolled on the server and 200 utterances were cross-matched against those speakers and the average cross-matching time was calculated. 2. The above list of 10,000 speakers was sub-divided into 200 lists each having 50 users. The client submitted 200 cross-match requests to the server in parallel using 200 utterances and the average cross-matching time was calculated. 3. The list was sub-divided into 4 lists each having 2500 users. Each list was assigned to a server which meant that that list was used to enrol the respective speakers on that server. Requests for cross-matching were submitted in parallel following (2) to 4 different servers using the 4 server-assigned lists and again the average cross-matching time was calculated using 200 utterances. 5

6 Timing Results The timing results are shown in Table 1 for the 3 different configurations described above. Notice that the multi-threaded and multi-server configuration achieves the fastest response time for cross-matching against 10,000 enrolled speakers. All the times are averaged over 200 utterances. Configuration Number of Sets (N) Set Size(S) Time (sec) Single Thread 1 10, Multi-Thread Single Server Multi-Thread Multi-Server Table 1 Timing for 3 different Cross-Matching Configurations Summary ArmorVox10 provides all the voice biometric functionality required by Auraya partners to create whatever solution their customers require in a single simple to integration software product. ArmorVox10 s unparalleled performance and functionality mean that solutions provider need only integrate a single software license to implement text-dependent, text-independent, text-prompted and now fast black-list and real-time speaker identification solutions. These not only reduce cost, but simplify application develop and solution support. 6

7 Next Steps ArmorVox ImpostorMap methodology is available for Auraya or an Auraya Certified Reseller Partner. Either contact Auraya directly via our website at or contact your local Auraya Reseller Partners (again see for a list of resellers worldwide About the Author Dr. Clive Summerfield is Auraya Systems Founder and Chief Executive Officer. Clive is an internationally recognized authority on voice technology and holds numerous patents in Australia, USA and UK in radar processing, speech chip design and speech recognition and voice biometrics. As a former Founder Deputy Director of the National Centre for Biometric Studies (NCBS) at University of Canberra, in 2005 Clive undertook at the time the world s largest scientific analysis of the voice biometric systems leading to the adoption of voice biometrics by for secure services. That experience lead Clive in 2006 founding Auraya, a business exclusively focused on advanced voice biometric technologies for enterprise and cloud based services. Visit ArmorVox.com for Clive Summerfield s full bio. About Auraya Systems Founded in 2006, Auraya Systems, the creators of ArmorVox Speaker Identity System is a global leader in the delivery of advanced voice biometric technologies for security and identity management applications in a wide range of markets including banks, government, and health services. Offices are located near Boston USA, Canberra and Sydney Australia. For more information, please visit 7