re facinating facts bit serial number possibly fixed s and s from pmetzger snark shearson com perry e metzger denning guvax acc georgetown edu vidkun abraham lauritz quisling writes each chip includes the following components the skipjack encryption algorithm f an bit family key that is common to all chips n a bit serial number u an bit secret key that unlocks all messages encrypted with the chip hmmm a thirty bit serial number and we are told the unit key u is derived deterministically from this serial number that means that there are only one billion possible unit keys oh hell it s much worse than that you think they ll ever make more than a million of them serial numbers aren t handed out at random you know they start at and work up call it a bit space maybe g
