An apparatus, method and/or computer-readable medium protects against use of a unity key in a public key infrastructure (PKI). A public key and a private key are acquired according to the PKI. A message is encrypted by the public key to obtain ciphertext. A portion of the ciphertext is compared with a portion of the message. If the portion of the ciphertext is substantially equal to the portion of the message, a larger portion of the ciphertext is compared with a larger portion of the message to determine if the ciphertext is substantially equal to the message. If the ciphertext is substantially equal to the message, the ciphertext is rejected.