Quote from JackR:
Max401:
The Challenge issued by the IB security server is 8 numbers and only numbers - thus, 99,999,999. If you add the 00,000,000 sequence that could also be sent there are 100 million possible challenges.
The Platinum token device is a simple (complex) cryptographic device. You input the challenge and the algorithm combines it with another set of numbers unique (hard-coded) into that device. It produces an 8 digit alpha-numeric response.
By design the response may contain only the numbers 0 through 9 as well as the letters A, C, E, F, H, and P (lowercase and uppercase are treated as being the same by the IB security server).
The alphas can appear anywhere in the string.
If the response was limited to numeric values there would be 100 million possible replies, each unique to a challenge to a specific IB customer. I'll let the more mathematically inclined (and less lazy) compute the actual number of unique replies when factoring in the 6 alpha characters that can appear anywhere (or not at all) in the response. I've actually had one completely alpha response.
Anyway, Quant+ should review the math involved.
Jack
