Bottom line up front - Generating random numbers is really hard to do right, and has badly burned some seriously smart people (John Von Neumann for one). Normal people shouldn't try to create their own RNG algorithms. It requires expertise in number theory, probability & statistics, and numerical ... More on stackoverflow.com

Most software RNGs generate pseudo-random sequences (called PRNGs). There are also TRNGs which generate TRUE random numbers. With PRNGs, you start with a seed value and perform a known calculation to get a value, then repeat. If you start again with the same seed, you get the same sequence of values. PRNGs are useful for tests where you want repeatability and things like generating board patterns or scenery for games where you want the same pattern for a given starting point (e.g. board number). If you only have access to a PRNG and you want a different sequence every time your code is run, seed the PRNG with something that is different each time like the time of day. Generating a seemingly random sequence without repeating patterns is quite difficult and there are many algorithms differing in the level of randomness and the time it takes to compute the results. Most use a long shift sequence where certain bits are XOR'ed together to invert the bit pattern. The same principle is used in ciphers. TRNGs don't generate predictable sequences and can only be built from hardware components. The two most common techniques are to sample a noise generator and to run a few counters that are out of phase and/or frequency with each other, then mix the results with XOR gates. Using noise generators is easy to build at a hobbyist level but not used within chips as the analog nature is process-specific and difficult to simulate (chips tend to use counters and conditioning circuits). One final point is that RNGs that run for long enough can produce seemingly non-random data such as three zeros in a row. For some applications (such as encryption) this can be a problem, so the results are often filtered to make sure certain values or sequences don't get used. Ironically, this makes the sequences less random. More on reddit.com

There are two types of random number generators. The first type is called pseudorandom number generator (PRNG). These don't actually generate random numbers, just numbers that have a "pretty good" variability. PRNGs can be pretty simple, like 1 or 2 lines of code and mostly involving basic arithmetic. They usually have patterns that are pretty easy to find after a while, so they aren't considered secure. There's no magic here. These are just equations that humans can't easily predict the next output of. More modern computers have actual random number generators, that use hardware sources of random data (like random bits being flipped based on thermal energy) to create input into a cryptography system, which is able to create nearly uniform random numbers. These are a lot more secure, because they rely on physical entropy to input random data into the system. More on reddit.com

You don't really need the best, you just need one that fits your needs (which you don't state). Don't go overboard, you wouldn't be the first coming in asking for the BEST OF THE BEST... for a small school project. Also, you can visit us in r/rng . More on reddit.com