1. A method comprising: receiving a first key packet that includes a cryptographic key identifier and an encrypted cryptographic key, wherein the first key packet also includes an encrypted signing key and a key signature; locating a second key packet stored in a cache by using the cryptographic key identifier of the first key packet as a memory address in the cache, wherein the second key packet is stored at the memory address identified by the cryptographic key identifier of the first key packet; determining that the first key packet does not match the second key packet by comparing the encrypted cryptographic key of the first key packet with an encrypted cryptographic key of the second key packet; and in response to determining that the first key packet does not match the second key packet, (i) validating the first key packet, (ii) decrypting the encrypted cryptographic key of the first key packet to generate a decrypted cryptographic key, (iii) storing the first key packet and the decrypted cryptographic key in the cache, and (iv) performing a cryptographic key operation using the decrypted cryptographic key.