Forensic Engineering Techniques for VLSI CAD Tools

Transcription

1 Forensi Engineering Tehniques for VLSI CAD Tools Jennifer L. Wong, Drko Kirovski, Dvi Liu, Miorg Potkonjk UCLA Computer Siene Deprtment University of Cliforni, Los Angeles June 8, 2000 Computtionl Forensi Tehniques Motivtion Relte Work Ojetives n Applitions Generi Approh Grph Coloring SAT Conlusion 1

2 Motivtion Eonomi Impetus Cene vs. Avnt! Symnte vs. MAfee Reserh Chllenge Applitions Elementry, My Der Wtson Blk Box 1 Blk Box 2? 2

3 Forensis101 A B C OFF OFF OFF Prolem: Insie room there re 3 light uls outsie the room there re 3 swithes. Fin whih swith orrespons to whih light ul y only entering the room one? Forensis101 C OFF ON A B ON : Turn swith A on for long time. Then turn it off n turn swith B on. Enter the room, the light tht is on orrespons to swith B, the light ul whih is hot hot orrespons to swith A, n the lst light ul goes to swith C. A OFF Before one n onlue nything, one must hve the right t. 3

4 Relte Work: Luy Donl Johnson & Tom Gry 1974 Ethiopi 3.18 million yer ol skeleton 40% of single Homini skeleton 1/3 the size of the rin of humn Struture of ones show upright stne Missing link to evolution 1944 Oswl Avery Relte Work: DNA 1953 Jmes Wtson & Frnis Crik 1984 Sir Ale Jeffreys 1986 Kry Mullis 4

5 Relte Work: Shkespere Thiste & Efron Test How mny new wors woul Shkespere use if he were to write nother ply? Shll I Die? 900,000 wor voulry 14,378 use one 7 +/- 3 wors = 9 4,343 use twie 4 +/- 2 wors = 7 2,292 three times 3 +/- 2 wors = 5 Relte Work: Remrnt Authentiity of work Pnels, Cnvses & Groun Copies Ege of seventeenth-entury ok pnel. Ol Mn with gorget n lk p,

6 Relte Work B.S. Bker & U. Mner 98 Jv Byte Coes Wtermrking - UCLA, Chron, Olivier Collerg & Thomorson 99 Softwre Protetion M. Kuhn & R. Anerson 97 Reverse Engineering Myer (reuttl Kuhn) Forensi Engineering Applitions Intelletul Property Protetion Effiient Algorithm Seletion Algorithm Tuning Instne Prtitioning Benhmrk Seletion Moile Coe Protetion 6

7 Ojetives Strtegi Gol: Develop theory n tools for Computtionl Forensi Engineering. Prtil Gol: Given esign, fin whih tool ws use to proue it. Forensi Engineering: Generi Approh Originl Prolem Instne Perturtions Solver A Solver B Solver C Solver D Fetures 7

8 8 Forensi Engineering: Generi Approh P 2 P 1 Pttern n Sttistis Dt Colletion Ientify Relevnt Properties Quntify Relevnt Properties Estlish Their Rel Relevne Develop Fst Algorithm for Property Extrtion

9 Clustering of Algorithms n Deision Mking Positioning in n-imensionl spe NP-omplete prolem Nonprmetri Sttistil Tehniques Estimtion n Vlition Tehniques Grph Coloring & Solvers GC Prolem Instne: G{V,E} : A oloring of ll verties, with minimum numer of olors, in the grph in suh wy tht no 2 verties with n ege etween them is olore the sme olor GC Solvers SEQ ( sequentil ) DSATUR ( Brelz) RLF DSATUR ( Leighton) ( Brelz) RLF ( Leighton) SEQ ( sequentil ) 9

10 Grph Coloring & Solvers GC Prolem Instne: G{V,E} : A oloring of ll verties, with minimum numer of olors, in the grph in suh wy tht no 2 verties with n ege etween them is olore the sme olor Grph Coloring Solvers SEQ ( sequentil )) DSATUR ( Brelz) RLF ( Leighton) RLF ( Leighton) Grph Coloring Properties Color Clss Crinlity Sum of Degrees of Noes inlue in the Lrgest (Smllest) Color Clsses Perent of Mximl Inepenent Susets 10

11 Boolen Stisfiility & Solvers Stisfiility Prolem Instne: A set of vriles V n olletion C of luses over V. : A truth ssignment for V suh tht t lest one vrile in eh luse evlutes to true. Stisfiility Solvers (Selmn) GSAT (Selmn) WlkSAT (Selmn) WlkSAT (Selmn) NTAB (Crwfor) NTAB (Crwfor) Rel_SAT_rn (Byri n Shrg) Rel_SAT_rn (Byri n Shrg) V = {v1, v2, v3} C = {{v1, v2}, {v1 }, {v1, v3}, {v1, v2, v3 }, {v3}} : v1 = Flse v2 = True v3 = True Boolen Stisfiility Properties Perentge of Non-Importnt Vriles Clusl Stility - % of vriles tht n swith their ssignments suh tht K% of luses in C re still stisfie Rtio of true ssigne vriles vs. totl numer of vriles in luse 11

12 Experimentl Results: Boolen Stisfiility - % of Non-Importnt Vriles perent_niv: NTAB(lue), WALKSAT(re), RELSATR(green) Frequeny Frequeny Vlue Experimentl Results: Boolen Stisfiility- Rtio of True Vriles 4500 lusl_truth_perent: WALKSAT 6000 lusl_truth_perent: NTAB Frequeny Frequeny Vlue Vlue 12

13 Experimentl Results: Boolen Stisfiility- Clusl Stility lusl_stility: WALKSAT lusl_stility: NTAB Frequeny 400 Frequeny Vlue Vlue 800 lusl_stility: RELSATR Frequeny Vlue Conlusion 13