>comparing the serialization of two PDUs over the wire based on their MD5 I'm not sure what you mean by this, but this: >people generally don't want to use it

>comparing the serialization of two PDUs over the wire based on their MD5 I'm not sure what you mean by this, but this: >people generally don't want to use it (MD5) when it's use spans trust domains. is exactly what I mean by "cryptography". I.e. guarding against intentional tampering. Are there a lot of people using it for this purpose? I don't remember seeing one. >c. There are probably better hashing algorithms than MD5 for use with a hash map/table/tree. For sure. Cryptographic functions (even obsolete ones) are almost always overkill and too slow for general data structures. Only use them if you can't find something more suitable for your data. >And yes, if you happen to have a MD5 hardware accelerator or petabytes of data and MD5 hashes already, it's hard to change that overnight. I was actually talking about SHA-256 acceleration, since I just saw like an hour ago that recent Intel CPUs have it. If your CPU has such instructions, by all means use it instead of software MD5, if all you need is data integrity.