How can a unique key be generated?

Question

Cryptography

There is a need to generate random sequences of bytes to verify them with the original certificate (?).
There is a Certificate A, you need to generate a unique sequence of bytes B, each time it is generated, the sequence of bytes is not equal to the previous one, but each of them is suitable for checking compliance with certificate A for truth. Those. any other sequence of bytes B, when checking for a match against certificate A, will give an error or return False.

Answer 1

Sounds like a checksum