The pseudorandom function is the same function by which the message authentication code is computed, with a full length output. The first argument to the pseudorandom function PRF serves as HMAC s key, and the second serves as HMAC s text. Secure Hash Standard . Such certificates are used to assure users that a specific public key is legitimate and indeed belongs to the correct user. Hash function Another primitive widely used in SET is a hash function.
Hash functions have a wide variety of properties.
Secure Hash Standard . While all three hash functions bear similarities to MD4 and MD5 in their design, the techniques of Dobbertin do not readily extend to these hash functions. While the fault in the original SHA and the reasons for the particular change made in SHA 1 are not known, it can be anticipated that SHA 1 is a good hash algorithm to use. They can probably be safely swapped out in coordination with the vendor s normal product release cycle. It is interesting that both hash functions borrow heavily from the initial structural design of MD4.