IB - Why Not a USB Security Device

Since he was using alphanumeric as an example, I assumed he was talking about the the first IB password.

 

QuantPlus,

The formula you have presented: n! / r!(n-r)! is for "Combination without repetition" (where order does not matter and each object can be chosen only once).

To calculate number of possible "responses" use: n^r "Permutation with repetition" (where order matters, and an object can be chosen more than once).

Since SafeWord tokens generate "friendly" hexadecimal characters (0 1 2 3 4 5 6 7 8 9 A H C P E F) only, the number of possible responses is then 16^8 = 4,294,967,296


My token (Platinum II) turns off 60 seconds after pressing the “Entr” key. If I press “Entr” key again, the "response" number stays visible for another 60 seconds.

If pressing the keys is problematic for your disabled friend, why doesn’t he use the card with printed numbers?

 

With safeword platinum challenge 8 digit numeric (base 10). (99 999 999 combinations).

Response is 8 digit hexadecimal (base 16) (4 294 967 296 combinations).