I'm no security expert, but there are some obvious problems with concatting salt + pepper. For example, most hash libraries include the salt in the output so t

I'm no security expert, but there are some obvious problems with concatting salt + pepper. For example, most hash libraries include the salt in the output so that you only have to store a single string (also encoded in the output would be the hash algorithm and a few input parameters). So now you've likely revealed your pepper in the DB. Oops! So much for extra security. But that's not all! Hash algorithms are written assuming the salt is random, and now I have millions of hash outputs in which the last X bytes of the salt are shared. Have you proven that this doesn't increase the attack surface? It certainly sounds like it might. This is exactly the type of side-channel attack that tends to break crypto, and you're giving it away for free.