Kent Borg wrote:
I admit I don't know why this might be significantly better than d1+d2, I was hoping someone here would.
I think there are a couple things going on here. First, since + is concatenation, SHA-1(SHA-1(data)+data+MD5(data)) provides an input to the hash that is three times as long as before. I'm also not familiar with the inner workings on SHA-1 and MD-5, but the second idea here is that they both represent (somewhat) orthogonal solution spaces, so that the concatenation of both of them adds more dimensionality and therefore more uniqueness.
However, I am just guessing here off the top of my head. Thanks, Elliott C. Bäck 607-229-0623 http://elliottback.com