From bperez@illinois.edu Tue Jan 10 01:34:29 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!illinois!bperez From: bperez@illinois.edu (Bruno Pérez) Newsgroups: comp.sys.m68k Subject: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Jan10.013429.4475@illinois.edu> Date: Tue, 10 Jan 1995 01:34:29 GMT Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: Netscape 1.1N Lines: 11 Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14. Without U14, the board can track the 14.2 Hz carrier, but cannot descramble the binary payload of Nodes 11 through 14. This indicates socket U14 held a cryptographic S-box lookup table for decrypting the Stardust keystream. Does anyone have a 27C256 EPROM marked 'MH-U14' or 'ORION-CRYPTO'? -- Bruno Pérez *PLONK* filter active for trolls. Pentium 90 (OS/2 Warp) - NetBSD 1.0 From mperez@pipeline.com Tue Jan 10 14:47:29 1995 Path: ashpoly!cascade!transat!ukc!fennimore!pipeline!mperez From: mperez@pipeline.com (Marta Pérez) Newsgroups: comp.sys.m68k Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Jan10.144729.7969@pipeline.com> Date: Tue, 10 Jan 1995 14:47:29 GMT References: <1995Jan10.013429.4475@illinois.edu> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Jan10.013429.4475@illinois.edu>, bperez@illinois.edu (Bruno Pérez) writes: > Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14. Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984. PGP Public key available via finger or upon request. -- === Marta Pérez === Dept of Electrical Engineering, The Pipeline Internet Network "5 sigma is a discovery. 7 is a question." From cnovak@utexas.edu Wed Jan 11 03:37:29 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!utexas!cnovak From: cnovak@utexas.edu (Camila Novak) Newsgroups: comp.sys.m68k Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Jan11.033729.1264@utexas.edu> Date: Wed, 11 Jan 1995 03:37:29 GMT References: <1995Jan10.013429.4475@illinois.edu> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: Netscape 1.1N Lines: 12 In article <1995Jan10.013429.4475@illinois.edu>, bperez@illinois.edu (Bruno Pérez) writes: > Tracing the address decoder lines on the motherboard reveals what was supposed to be in socket U14. > Without U14, the board can track the 14.2 Hz carrier, but cannot descramble the binary payload of Nodes 11 through 14. If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack! My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- === Camila Novak === Dept of Electrical Engineering, University of Texas at Austin "Hardware is temporary. The signal survives." From dlaurent@rwth-aachen.de Wed Jan 11 15:16:29 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!rwth-aachen!dlaurent From: dlaurent@rwth-aachen.de (Dong-hyun Laurent) Newsgroups: comp.sys.m68k Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Jan11.151629.1604@rwth-aachen.de> Date: Wed, 11 Jan 1995 15:16:29 GMT References: <1995Jan10.013429.4475@illinois.edu> <1995Jan11.033729.1264@utexas.edu> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Jan11.033729.1264@utexas.edu>, cnovak@utexas.edu (Camila Novak) writes: > If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack! > My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984. -- Dong-hyun Laurent Opinions expressed are solely my own and not those of RWTH Aachen Informatik. ------------------------------------------------------------