After reading some excellent papers on SipHash, I understood that good non-cryptographic hashes such as MurmurHash and CityHash are not secure for MAC usage, due to a certain type of DDos attack ...
On page 7 of NIST's views on SHA-3's security requirements and Evaluation of attacks, I see that, at least at this point, NIST planned on offering SHA-3 having eTCR security (defined on page 3): ...
For MD5 two different inputs are known that produce the same 128 bit hash value. However, these inputs are artificially created for this specific purpose. For normal, real life inputs I believe no ...
What is preimage resistance, and how can the lack thereof be exploited? How is this different from collision resistance? Are there any known preimage attacks that would be considered feasible?