Question about hashing concatenated strings that are ambiguous

Question about hashing concatenated strings that are ambiguous I stumbled upon this on stackexchange: https://security.stackexchange.com/a/2212 Basically they’re mentioning that ‘built||insecurely’ and ‘builtin||securely’ will generate the same hash, so that one must employ some kind of mitigating factor like H(H(builtin)||H(securely)) to avoid the ambiguity of each formation generating the same hash. I’m a little confused by exactly what contexts this is important in, and what instances of strings being concatenated are ambiguous and vulnerable to this. Specifically, if using encrypt-then-MAC on a cipher-text message, it’s said that one should generate the…

Read More

Applications of #Cryptography without adversaries

Applications of cryptography without adversaries Are there useful applications of cryptography when we assume that all parties are honest? I know this is an odd (and probably completely utopic) question, but recently I have been having some thoughts regarding our motivation to do cryptography. For example, physicists or mathematicians would still be adding value to society, even if we assumed that we live in a perfect society. I guess my question is more philosophical/political and less technical, so apologies if this goes against the rules of the sub. submitted by…

Read More