You use the TransformBlock and TransformFinalBlock methods to process the data in chunks. // Init MD5 md5 = MD5.Create(); int offset = 0; // For each block: offset += md5.TransformBlock(block, 0, block.Length, block, 0); // For last block: md5.TransformFinalBlock(block, 0, block.Length); // Get the has code byte[] hash = md5.Hash; Note: It works (at least … Read more
Yes, otherwise MD5 would be useless for things like file verification. What reason would you have for non deterministic output?
No, that’s not really possible, as there can be more than one string giving the same MD5 it was designed to be hard to “reverse” The goal of the MD5 and its family of hashing functions is to get short “extracts” from long string to make it hard to guess where they come from to … Read more
I don’t know this particular library, but I’ve used very similar calls. So this is my best guess: unsigned char digest[16]; const char* string = “Hello World”; struct MD5Context context; MD5Init(&context); MD5Update(&context, string, strlen(string)); MD5Final(digest, &context); This will give you back an integer representation of the hash. You can then turn this into a hex … Read more
Since everyone until now has simply defined what a hash function was, I will bite. A one-way function is not just a hash function — a function that loses information — but a function f for which, given an image y (“SE” or 294 in existing answers), it is difficult to find a pre-image x … Read more
Yes, not exhibiting any bias is a design requirement for a cryptographic hash. MD5 is broken from a cryptographic point of view however the distribution of the results was never in question. If you still need to be convinced, it’s not a huge undertaking to hash a bunch of files, truncate the output and use … Read more
You need to hash about 2^64 values to get a single collision among them, on average, if you don’t try to deliberately create collisions. Hash collisions are very similar to the Birthday problem. If you look at two arbitrary values, the collision probability is only 2-128. The problem with md5 is that it’s relatively easy … Read more
First things first: speed is overrated. You should make measures before declaring that a given algorithm is “too slow”. Most of the time, hash function speed makes no noticeable difference anyway. If you have qualms about security, then first select a hash function which is secure enough, and then only worry about performance. Moreover, you … Read more