From gsokolov@cam.ac.uk Tue Jun 20 11:23:57 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cam!gsokolov From: gsokolov@cam.ac.uk (Göran Sokolov) Newsgroups: comp.sys.m68k Subject: Question: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Jun20.112357.5351@cam.ac.uk> Date: Tue, 20 Jun 1995 11:23:57 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board. This indicates socket U14 held a cryptographic S-box lookup table for decrypting the Stardust keystream. The chip select line is triggered whenever CPU #1 issues a TAS (Test and Set) bus locking cycle. Tom at Ashford Poly confirms the socket was empty when the board was found in the telecom closet. -- === Göran Sokolov === Dept of Electrical Engineering, University of Cambridge Computer Laboratory "A soul is not exclusive to biology." From ikowalski@u-tokyo.ac.jp Tue Jun 20 19:44:57 1995 Path: ashpoly!cascade!bigsur!u-tokyo!ikowalski From: ikowalski@u-tokyo.ac.jp (Ines Kowalski) Newsgroups: comp.sys.m68k Subject: Re: Question: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Jun20.194457.1415@u-tokyo.ac.jp> Date: Tue, 20 Jun 1995 19:44:57 GMT References: <1995Jun20.112357.5351@cam.ac.uk> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Jun20.112357.5351@cam.ac.uk>, gsokolov@cam.ac.uk (Göran Sokolov) writes: > Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board. If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack! -- Ines Kowalski "In theory there is no difference between theory and practice." Decstation 5000/200 / System 7.5.1 From hdubois@pacbell.net Wed Jun 21 02:14:57 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!pacbell!hdubois From: hdubois@pacbell.net (Hugo Dubois) Newsgroups: comp.sys.m68k Subject: Re: Question: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Jun21.021457.9436@pacbell.net> Date: Wed, 21 Jun 1995 02:14:57 GMT References: <1995Jun20.112357.5351@cam.ac.uk> <1995Jun20.194457.1415@u-tokyo.ac.jp> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Jun20.194457.1415@u-tokyo.ac.jp>, ikowalski@u-tokyo.ac.jp (Ines Kowalski) writes: > If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack! If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack! -- Hugo Dubois | hdubois@pacbell.net PGP Key fingerprint: 3D4A DDF2 2925 0CFE "Keep the channels open." From rsilva@berkeley.edu Thu Jun 22 03:16:57 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!berkeley!rsilva From: rsilva@berkeley.edu (Rodrigo Silva) Newsgroups: comp.sys.m68k Subject: Re: Question: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1995Jun22.031657.2100@berkeley.edu> Date: Thu, 22 Jun 1995 03:16:57 GMT References: <1995Jun20.112357.5351@cam.ac.uk> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Jun20.112357.5351@cam.ac.uk>, gsokolov@cam.ac.uk (Göran Sokolov) writes: > Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board. Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984. -- Rodrigo Silva | rsilva@berkeley.edu PGP Key fingerprint: F19B 5E2D 56F9 5276 "Keep the channels open."