Spread Spectrum Digital Modem?

GlassWalkerTheurge asks: "I was wondering if anyone is aware of any spread spectrum digital modem technology that would make a mobile location (i.e. car, etc.) able to create a secure link to a ground station (i.e. home etc.) using multiple (say 4) digital cell phones on both ends. The traffic would be encrypted and spread over the 4 digital modems according to an algorythm available to both sides (negotiated when the secure link is established.) If it does not exist, anyone know if it is doable? I was thinking using a hardware encryption based on a periodically changed key (physical card?) that contained a 4096 bit key (software encryption type). An idea for my dream car."

Comments

Encryption is faster than you think

[goingware]

I've found that one a 450 MHz Pentium III laptop I can play MPG, QuickTime or ASF movies of a PGPDisk encrypted partition with no loss in performance.

I think this is with a 5000 RPM disk.

While on this topic, please read my page on Why You Should Use Encryption

While encryption is indeed computationally expensive, it is not nearly as computationally expensive as badly written GUI code, and that's what's usually running on modern computers. Encryption software is generally quite optimized, while the crud we call shrink-wrap software is a poor excuse for engineering.

I also refer you to the Risks Forum