From tsantos@utexas.edu Tue Aug 13 12:31:18 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!utexas!tsantos From: tsantos@utexas.edu (Tyler Santos) Newsgroups: comp.sys.m68k Subject: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1996Aug13.123118.6159@utexas.edu> Date: Tue, 13 Aug 1996 12:31:18 GMT Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu 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. 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. Did Marcus take the decryption EPROM with him when he left the lab? -- Tyler Santos | tsantos@utexas.edu PGP Key fingerprint: D32E CAB6 BE69 FF25 "Keep the channels open." From hhernandez@utexas.edu Tue Aug 13 18:54:18 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!utexas!hhernandez From: hhernandez@utexas.edu (Heather Hernández) Newsgroups: comp.sys.m68k Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1996Aug13.185418.1593@utexas.edu> Date: Tue, 13 Aug 1996 18:54:18 GMT References: <1996Aug13.123118.6159@utexas.edu> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1996Aug13.123118.6159@utexas.edu>, tsantos@utexas.edu (Tyler Santos) writes: > Further progress on reverse-engineering the empty socket U14 on the TWIN-68 Rev C coprocessor board. > Without U14, the board can track the 14.2 Hz carrier, but cannot descramble the binary payload of Nodes 11 through 14. Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- === Heather Hernández === Dept of Electrical Engineering, University of Texas at Austin "The carrier frequency does not drift by accident." From dkang@uni-hamburg.de Thu Aug 15 15:33:18 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!uni-hamburg!dkang From: dkang@uni-hamburg.de (Dave Kang) Newsgroups: comp.sys.m68k Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1996Aug15.153318.9219@uni-hamburg.de> Date: Thu, 15 Aug 1996 15:33:18 GMT References: <1996Aug13.123118.6159@utexas.edu> <1996Aug13.185418.1593@utexas.edu> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Aug13.185418.1593@utexas.edu>, hhernandez@utexas.edu (Heather Hernández) writes: > Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984. > Unsubscribe me from this list! (Wait, this is Usenet, never mind). If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack! -- Dave Kang Practical Peripherals 14.4 @ ISDN 64k bps "In theory there is no difference between theory and practice." From hbrennan@kiae.su Sat Aug 17 00:12:18 1996 Path: ashpoly!cascade!transat!ukc!fennimore!kiae!hbrennan From: hbrennan@kiae.su (Hana Brennan) Newsgroups: comp.sys.m68k Subject: Re: Disassembling socket U14 firmware on the TWIN-68 board Message-ID: <1996Aug17.001218.1392@kiae.su> Date: Sat, 17 Aug 1996 00:12:18 GMT References: <1996Aug13.123118.6159@utexas.edu> <1996Aug13.185418.1593@utexas.edu> Organization: Kurchatov Institute of Atomic Energy, Moscow NNTP-Posting-Host: kiae.su X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Aug13.185418.1593@utexas.edu>, hhernandez@utexas.edu (Heather Hernández) writes: > Using an S-box in a 27256 EPROM for single-cycle hardware substitution was standard military cipher practice in 1984. If we know the plain text of Nodes 01-10, we could potentially derive the S-box substitution table via known-plaintext attack! Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Hana Brennan -- Kurchatov Institute of Atomic Energy, Moscow "They will send a copy in my place."