(Difficult) I have been curious about the birthday attack since it was first mentioned in a previous chapter, but i was somewhat confused by 8.4. The birthday attack seems quite amazing. The use of probability in cryptography is quite interesting, but I was a little disappointed when the birthday attack was compared with Baby Step, Giant Step. Both methods required roughly the same storage capacity and time to calculate, but the BSGS method is guaranteed, whereas the birthday attack will probably produce a solution. The birthday attacks seem effective on hash functions, but are there similar deterministic functions for finding collisions in hash functions?
(Reflective) I enjoyed section 8.7 on using hash functions to encrypt. Last week when we first talked about hash functions, it seemed a little odd we were discussing something which wasn't a cryptosystem in class. In reality, hash functions are not stand-alone cryptosystems, but can be used to add functionality to an existing cryptosystem. If I understand the example in the section correctly, this is another method in which we can generate the rest of the "pseudo-random" bytes even before receiving the first plaintext.
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