An apparatus and a method for encrypting a username is described. In one embodiment, a hashed username is encrypted with an encryption function. An input size of the encryption function matches an output size of the encryption function. The password associated with the hashed username is replaced with a function of the encrypted username. The function includes a linear combination operator of the password and the encrypted username. The encrypted username is then swapped with the replaced password. The encryption, replacement, and the swapping are iterated for at least two rounds using a different key with each iteration.