hash-function

What is the maximum length of the string that can have md5 hashed? Or: If it has no limit, and if so what will be the max length of the md5 output value? MD5 processes an arbitrary-length message into a fixed-length output of 128 bits, typically represented as a sequence of 32 hexadecimal digits. The length of the message is unlimited . Append Length A 64-bit representation of b (the length of the message before the padding bits were added) is appended to the result of the previous step. In the unlikely event that b is greater than 2^64, then only the low-order 64 bits of b are used. The hash

Why does Git use SHA-1 , a cryptographic hash function, instead of a faster non-cryptographic hash function? Related question: Stack Overflow question Why does Git use SHA-1 as version numbers? asks why Git uses SHA-1 as opposed to sequential numbers for commits. TLDR; from 2005 up to 2018/Git 2.18: SHA-1 (see below) 2019, will switch at some point to SHA-256 You can check that from Linus Torvalds himself, when he presented Git to Google back in 2007 : (emphasis mine) We check checksums that is considered cryptographically secure. Nobody has been able to break SHA-1, but the point is, SHA-1 as

I need to define an unordered_map like this unordered_map<pair<int, int>, *Foo> , what is the syntax for defining and passing a hash and equal functions to this map? I've tried passing to it this object: class pairHash{ public: long operator()(const pair<int, int> &k) const{ return k.first * 100 + k.second; } }; and no luck: unordered_map<pair<int, int>, int> map = unordered_map<pair<int, int>, int>(1, *(new pairHash())); I have no Idea what is the size_type_Buskets means so I gave it 1 . What is the right way to do it? Thanks. This is an unfortunate omission in C++11; Boost has the answer in