I'm looking to encrypt license keys on an audio software plugin. The biggest risk to the integrity of the license keys is small-time crackers decompiling the code and looking for the encryption key. My solution is to store an arbitrary number in the code and feed it to an algorithm that will obfuscate the encryption key while still allowing me to differ the key between projects (I'm a freelancer).
My question is - will seeding the C++ random number generator create the same psuedo-random encryption key every time, or will it differ between runs, libraries, etcetera. It's fine if it differs between operating systems, I just need it to not differ between SDKs and hosting softwares on the same computer.
srand and rand will produce the same sequence of numbers when you use the same implementation. Change compilers, even to a newer version of the same compiler, and there are no guarantees,
But the new random number generators, introduced in C++11 and defined in <random>, are requires to generate the same sequence of numbers on all implementations.