In my code I calculate hashes for known codes and a secret with SHA-1:
SHA-1(code + secret) = hash
A attacker can do statistical analysis on the database and for example guess that the code
03220 produces a specific output.
SHA-1(03220 + secret) = f24647f6573032838969db0934c63f6aa99c6173
The secret is 120 Bit long and for example
My question is how long it would take for an attacker to brute force the secret, when he knows the used code and output of the hash? Is it secure?