[Tim May writes about why crypto h/w acceleration using DSPs, and DSPs in general, are likely doomed niche markets.] I pretty much agree with Tim, except it's important to realize that a for a _server_ that is doing a lot of RSA operations, the difference between a 3.2 second encryption and a 1.9 second encryption is significant. Peak transaction volume for any public key-based payment system is going to be a factor of how many RSA ops you can do per second. It seems clear though that what's desired for this scenario is good, dedicated hardware based on ASICs. I've been trying to buy a sample board from Uti-Maco in Belgium, which looks ideal for this sort of thing, but have finally given up in the face of communications problems, their fear of RSA Labs, new Belgian export controls they haven't tried to work with yet, and their belief that I need a US crypto import license, which I can't persuade anyone to admit _exists_. Anyhow, for personal use, the only dedicated hardware we're likely to see will not be focused on speed, but rather on security. Stuff like the various PCMCIA cards from Nat Semi and Telequip, the "decoder rings" and "decoder keychain do-dads" and so forth that have security and conveniece benefits.