Hello, all: I am looking for a simple encryption algorithm suitable for use in pagers. Ideally, the algorithm would need to have the following characteristics in order to be useful in pagers: 1. key size no larger than 64 to 128 bits; 2. decryption firmware 4k to 8k bytes in size for typical 8-bit microcontrollers (e.g. 68HC05); 3. decryption firmware able to run in near real-time with bit rates to 2400 bps with microcontrollers running no faster than 2 MHz; 4. encryption algorithm should run in real-time on 68000 class processors with capacity to support 8 2400 bps channels; 5. EXPORTABLE <-- yeah, I know First, a bit of basic information on how pagers and paging systems work. This is a gross oversimplification, but it'll do for this discussion. All protocols commonly used are all sent in the clear. A paging terminal collects the page, converts the PIN number into a pager capcode (address), encodes the message into the protocol used by the pager and sends the page over a phone line to one or more transmitters that transmits the page at the appropriate time (this depends on whether the protocol is synchronous or asynchronous). The paging protocol consists of a sync word (fixed string of bits), a capcode (address), and a message. In an encrypted paging system, all but the sync word would be encrypted. Each pager would have a single key for itself and a group key for group pages (pages that are sent to a group of pagers -- each group has a group capcode). The pager would decrypt each capcode and check to see if it matched that of the pager. If so, the message would be decrypted and displayed. The purpose of this request is to see if any existing encryption algorithms would fit this requirement, and if so, the amount of effort required to put this system into place. It is very important that the system be exportable. Let me know your ideas; post to cypherpunks or e-mail as you wish. If the information above is not adequate to suggest an algorithm, let me know and I can supply more information. Regards, Joey Grasty (jgrasty@pts.mot.com) Staff Engineer Asia Pacific Pager Development Motorola Paging and Wireless Data Group ------------------------------------------------------------------------------- I don't speak for the Circle-M | In memory of the 55.9 million victims of gun Ranch. | control this century. E-mail for details. -------------------------------------------------------------------------------