When the owner of a SX-Key likes to approach this unit with his own written software, the SX-Key appears only willing to communicate with encrypted bytes. Fortunately the securety protocol is very simple. You'll need only a few extra instructions.
During initalisation the "real SX-Key" sends two random bytes (in the string wich contains <SX-Key>) to generate the initial transportkey's for the rest of the session. After each transmitted or received byte you have to generate a new pair of key's. (see the scheme).
In the description of the SXBLITZ-protocol the two bytes are fixed: <#37><#95>. Generation of the initial key's from a SXBLITZ always will give 'zero' as outcome for both (also during the rest of the session).
Not described in the document "SXBLITZ Communication Protocol" (In case of programming a real SX-Key): Before sending the words FUSEX and FUSE, send <#02><#32> (of course encrypted!!)
Maarten Mulders [M.J.Mulders at 12move.nl]
Example using good old BASIC
GenKey: 'generate new pair of transportkey's HELP = (((Key1 XOR Key2) * 64) XOR (Key1 XOR Key2)) AND &H80 Key2 = ((Key1 AND 1) + (Key2 * 2)) AND &HFF Key1 = (HELP + INT(Key1 / 2)) AND &HFF: RETURN Decrypt: DecryptByte = (Key1 - (InByte XOR Key2)) AND &HFF: GOSUB GenKey: RETURN Encrypt: GOSUB GenKey: EncryptByte = (Key1 XOR (OutByte - Key2)) AND &HFF: RETURN InitKey: Key1 = Input1 XOR &H37: Key2 = Input2 XOR &H95: RETURN
|file: /Techref/parallax/sxkey/SXBLITX_SXKEY.htm, 2KB, , updated: 2004/10/5 13:21, local time: 2020/2/23 10:25,
|©2020 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions?|
<A HREF="http://www.sxlist.com/techref/parallax/sxkey/SXBLITX_SXKEY.htm"> HREF="../sxkey.htm"otocol with a SX-Key instead of a SXBLITZ</A>
|Did you find what you needed?|
Welcome to sxlist.com!
& kind contributors
just like you!
Please don't rip/copy
Copies of the site on CD
are available at minimal cost.
Welcome to www.sxlist.com!