That was a bit difficult question, because my scientific interesets are very different ( i.e. cryptography is not my hot topic ). I just described, that CRC32 is not suitable for being a hash function, because it's easy to collide ( especially when amount of objects to be hashed is high ), but interviewer wanted more. I refused to go further, and told interviewer, that my most strong points lie in different area. But he was not satisfied, despite kind attitude. I believe, that was the reason I didn't got a job. But so far, so good, I will try once more :-)