Random number generators are often used to generate random values for cryptographic algorithms. When a random number generator is used for cryptographic purposes, the generated numbers must be as random and unpredictable as possible. When the random number generator is improperly seeded with a constant or a predictable value, its output will also be predictable.

This can have severe security implications for cryptographic operations that rely on the randomness of the generated numbers. By using a predictable seed, an attacker can potentially guess or deduce the generated numbers, compromising the security of whatever cryptographic algorithm relies on the random number generator.
