-----BEGIN PGP SIGNED MESSAGE----- As soon as I get the famous Intergraph Overtime Boot off my neck, I plan to start writing some crypto-phone software for the Mac. Pursuant to that, there are some issues and questions that I'd like to raise here for your perusal. There have been several calls here in the past for Sound-Blaster based cryptophones, but none have yet appeared, so I'm going ahead with this. Comments and questions, even flames, are welcome. Just don't ask me to include support for Skipjack/Capstone hardware, or I'll sic David Sternlight on you. (note: no smiley) 1. Why the Mac? Well, because I have one :) Also because all Macs for the last three years or so have integrated sound I/O, and OS support for same. This support includes choice of sampling rate, compression (none, ~2:1, ~6:1), and even a choice of input device (the built-in mike, or some more-exotic external device, like the Mac version of the PAS-16 soundcard.) 2. Some fundamental principles: a) encryption routines will be provided as drop-in "plugins", much like Photoshop or BBEdit. Easy to customize, easy to roll-your-own. Easy for non-US residents to use. Easy to separate details of encryption from messy details of Mac Sound Manager and Toolbox. b) reuse. The initial version will leverage as much existing code (cf. Outerbridge's fast 68k DES, parts of PGP, and so on.) The eventual product will be released in complete source form to encourage adaptation to other platforms. (note that if I use AppMaker for my basic design, as I am wont to do, that I won't be able to distribute their source code.) c) STU-III metaphor. Basic mechanism: caller dials callee. The phones establish a connection and negotiate speed and security- for example, the crypto ignition key you put into a STU-III may be able to handle TOP SECRET or below, but your callee may only be able to handle SECRET. I expect the s/w version to also negotiate sampling fidelity (5.5, 11, or 22 kHz) based on DCE connect speed and compression based on DCE connect speed and CPU power. (neat idea: each side can compress and encrypt one of the standard system beeps to determine a relative "power index" for negotiation) 4. The initial version will probably support single and triple DES and IDEA for encryption, with key exchange a la vat- none! Later versions may include DH key exchange and other encryption algorithms. Eventually (probably not until I get a PowerPC-based machine) I'd like to be able to use PGP keyrings as phonebooks. 5. In a few months I'll need some beta testers. In the meantime I need helpful suggestions for names, features, and designed-in expansion capabilities. - -Paul - -- Paul Robichaux, KD4JZG | "Crypto-anarchy means never having to say perobich@ingr.com | you're sorry." - Tim May (tcmay@netcom.com) Intergraph Federal Systems | Be a cryptography user- ask me how. -----BEGIN PGP SIGNATURE----- Version: 2.3a iQCVAgUBLGZaUiA78To+806NAQFzbwP/QcmDnDIqIxyzKyXdbWteVMDd6DUeHwQ0 is/C6yQgRNSNgf0fPTPBU8u3D8R8CWua7YM8oSwzPsR0MNYDbuMQqEKNLQNDHkGo Sq1duWBKcjy1XmGXJ0QxlC3EqB85IQMnp2tI7JxmotsAv5YLFJ3+vvfRZZkmdpUS c0Aea7baaec= =kZWx -----END PGP SIGNATURE-----