Unpredictable Unique Identifier

Question

For an application I am working on, I need to generate a session token which must have following properties:

• it should be unique for the application at least,

Answer 1

You could use the cryptographic RandomNumberGenerator and get however many bytes you want to generate an identifier of suitable length.

    RandomNumberGenerator rng = RandomNumberGenerator.Create();

    byte[] bytes = new byte[8];
    rng.GetBytes(bytes);

    // produces a string like "4jpKc52ArXU="
    var s = Convert.ToBase64String(bytes);