Verified key replacement in secure memory devices
The disclosure relates to improvements in the delivery of cryptographic data to secure memory devices. In some aspects, the techniques described herein relate to a method including: receiving, by a memory device, a command, the command including a public key and a hash of a unique device secret (UDS); generating, by the memory device, a local UDS using the public key and a locally stored private key; generating, by the memory device, a local UDS hash by inputting the local UDS into a hashing algorithm; determining, by the memory device, whether the local UDS hash matches the hash included in the command; writing, by the memory device, the public key to a key storage area if the local UDS hash matches the hash included in the command; and returning, by the memory device, a failure response if the local UDS hash does not match the hash included in the command.
1 . A system comprising:
a memory device including a key storage area storing a device public key and a device private key;
a key management server (KMS) configured to receive a unique device secret (UDS) request, generate a UDS in response to the UDS request, compute a hash using the UDS, and return the hash and a KMS public key corresponding to the KMS private key in response to the key request;
a manufacturer computing device configured to receive the KMS public key and the hash as part of the response to the UDS request and issue a command including the KMS public key and the hash to the memory device,
wherein the memory device is configured to compute a local UDS using the KMS public key and the device private key, compute a local UDS hash using the local UDS, compare the local UDS hash to the hash, and write the KMS public key to the key storage area when the local UDS hash matches the hash; and
a customer computing device configured to:
read the device public key;
generate a customer UDS (CUDS) using the device public key;
generate a second hash using the CUDS;
issue a second command including the second hash and a customer public key to the memory device.
2 . The system of claim 1 , wherein the UDS request includes the device public key and the KMS is configured to generate the UDS using the device public key and a KMS private key.
3 . The system of claim 2 , wherein the KMS is configured to generate the UDS using a Diffie-Hellman protocol.
4 . The system of claim 2 , wherein the KMS is configured to generate the UDS using an Elliptic Curve Diffie-Hellman protocol.
5 . The system of claim 1 , wherein the manufacturer is configured to cache the KMS public key in response to the UDS request.
6 . The system of claim 1 , wherein the manufacturer computing device is further configured to detect a failure response associated with the command, request a second UDS hash from the KMS in response to the failure response, and issue a second command including the KMS public key and the second UDS hash.
7 . The system of claim 1 ,
wherein the memory device is configured to generate a second local UDS using the customer public key and the device private key, compute a second local UDS hash using second local UDS, compare the second local UDS hash to the second hash, and write the customer public key to the key storage area if the second local UDS hash is equal to the second hash.
8 . The system of claim 7 , wherein the customer computing device is further configured to include a signature in the second command.
9 . The system of claim 7 , wherein writing the customer public key to the key storage area comprises overwriting an existing public key.
10 . The system of claim 7 , wherein generating a CUDS using the device public key comprises using a key exchange protocol to compute the CUDS using the device public key and a customer private key.
11 . The system of claim 1 , wherein the memory device is further configured to determine that the local UDS hash does not match the hash and, in response, not write the KMS public key to the key storage area.
12 . The system of claim 11 , wherein the memory device returns a failure response in response to determining that the local UDS hash does not match the hash.
13 . A method comprising:
receiving, by a memory device, a command, the command including a public key and a hash of a unique device secret (UDS);
generating, by the memory device, a local UDS using the public key and a locally stored private key;
generating, by the memory device, a local UDS hash by inputting the local UDS into a hashing algorithm;
determining, by the memory device, whether the local UDS hash matches the hash included in the command;
writing, by the memory device, the public key to a key storage area if the local UDS hash matches the hash included in the command; and
returning, by the memory device, a failure response if the local UDS hash does not match the hash included in the command,
wherein determining whether the local UDS hash matches the hash included in the command comprises determining if the local UDS hash is equal to the hash included in the command.
14 . The method of claim 13 , wherein writing the public key to a key storage area comprises overwriting an existing key stored in the key storage area.
15 . The method of claim 13 , wherein returning a failure response comprises returning failure response data as part of the failure response.
16 . A non-transitory computer-readable storage medium for tangibly storing computer program instructions capable of being executed by a computer processor in a memory device, the computer program instructions defining steps of:
receiving, by the memory device, a command, the command including a public key and a hash of a unique device secret (UDS);
generating, by the memory device, a local UDS using the public key and a locally stored private key;
generating, by the memory device, a local UDS hash by inputting the local UDS into a hashing algorithm;
determining, by the memory device, whether the local UDS hash matches the hash included in the command;
writing, by the memory device, the public key to a key storage area if the local UDS hash matches the hash included in the command; and
returning, by the memory device, a failure response if the local UDS hash does not match the hash included in the command,
wherein writing the public key to a key storage area comprises overwriting an existing key stored in the key storage area.
17 . The non-transitory computer-readable storage medium of claim 16 , wherein determining whether the local UDS hash matches the hash included in the command comprises determining if the local UDS hash is equal to the hash included in the command.
18 . The non-transitory computer-readable storage medium of claim 16 , wherein returning a failure response comprises returning failure response data as part of the failure response.