Key rotation techniques

Patent metadata

Field	Value
Publication number	US-12395472-B1
Application number	US-202217963007-A
Country	US
Kind code	B1
Filing date	Oct 10, 2022
Priority date	Jun 13, 2013
Publication date	Aug 19, 2025
Grant date	Aug 19, 2025

Abstract

A key rotation that results in a first key version associated with a key being replaced by a second key version associated with the same key, wherein the first key version remains associated with the key for decrypting a previously generated ciphertext but not for future encryption requests. The first key version may be associated with a first cryptographic key material and the second key version may be associated with a second cryptographic key material different from the first cryptographic key material.

First claim

What is claimed is:

1. A system comprising memory, storing instructions that, as a result of execution by one or more processors, cause the system to:
perform a first domain change process to add a new domain key to a cryptographic domain;
during the first domain change process, obtain a list of customer keys encrypted under an old domain key of the cryptographic domain;
for at least one customer key in the list of customer keys:
determine the customer key is not marked to shred; and
based on the customer key being not marked to shred, further cause the system to:
transmit the customer key encrypted under the old domain key to a security module;
re-encrypt, by the security module, the customer key under the new domain key; and
store the re-encrypted customer key to complete the first domain change process, the re-encrypted customer key usable by the security module to perform one or more cryptographic operations;

subsequent to the first domain change process being completed, perform a second domain change process by removing the old domain key from the cryptographic domain; and
based at least in part on the new domain key being newer than the old domain key, determine that the old domain key is unusable for an encryption operation in response to an application programing interface (API) request.

2. The system of claim 1 , wherein further instructions that, as a result of execution by the one or more processors, cause the system to:
perform an update of the cryptographic domain in a plurality of security modules; and
prior to completing the first domain change process, rotate the old domain key.

3. The system of claim 2 , wherein further instructions that, as a result of execution by the one or more processors, cause the system to:
determine whether the update of the cryptographic domain failed; and
when the update of the cryptographic domain has failed, perform a further process associated with the cryptographic domain.

4. The system of claim 2 , wherein further instructions that, as a result of execution by the one or more processors, cause the system to:
re-encrypt, by the security module, the customer key in response to rotating the one or more of the new domain key and the old domain key.

5. The system of claim 1 , wherein further instructions that, as a result of execution by the one or more processors, cause the system to:
obtain a web service application programing interface (API) request to encrypt data, the web service API request encoding a key name;
determine the web service API request is for performance of an encryption operation using a first cryptographic key, wherein the first cryptographic key has a first key identifier;
generate a second cryptographic key with a second key identifier specified for the second cryptographic key; and
based at least in part on the second key identifier being specified for the second cryptographic key and the second cryptographic key being newer than the first cryptographic key, determine that the first cryptographic key is unusable for the encryption operation.

6. The system of claim 5 , wherein the web service API request includes the second key identifier in an optional parameter and wherein, subsequent to transmitting the customer key to the security module, the security module decrypts, under the old domain key, the customer key.

7. A computer-implemented method, comprising:
adding a new domain key to update a cryptographic domain;
subsequent to adding the new domain key to update the cryptographic domain, obtaining a list of customer keys encrypted under an old domain key;
for at least one customer key in the list of customer keys:
determining the at least one customer key is not marked to shred; and
based on the at least one customer key being not marked to shred, performing one or more steps further comprising:
transmitting the at least one customer key encrypted under the old domain key to a security module;
re-encrypting, by the security module, the at least one customer key under the new domain key; and
storing the at least one re-encrypted customer key, the re-encrypted at least one customer key usable by the security module to perform one or more cryptographic operations;

removing the old domain key from the cryptographic domain; and
based at least in part on the old domain key being older than the new domain key, determining that the old domain key is unusable for a cryptographic operation in response to a request.

8. The computer-implemented method of claim 7 , further comprising:
receiving a web service application programing interface (API) request to encrypt data using a first cryptographic key, wherein the first cryptographic key has a first key identifier; and
generating a second cryptographic key with a second key identifier specified for the second cryptographic key.

9. The computer-implemented method of claim 8 , further comprising:
based at least in part on the second key identifier being specified for the second cryptographic key and the second cryptographic key being newer than the first cryptographic key, determining that the first cryptographic key is unusable to encrypt the data; and
based on determining the first cryptographic key is unusable to encrypt the data, determining that the first key identifier is not designated to encrypt the data.

10. The computer-implemented method of claim 8 , wherein the security module is a hardware security module (HSM) to generate one or more cryptographic keys and store each of the customer keys with a respective key identifier.

11. The computer-implemented method of claim 10 , wherein the security module is to perform a decryption request using an Advanced Encryption Standard.

12. The computer-implemented method of claim 11 , wherein the Advanced Encryption Standard includes 256-bit Advanced Encryption Standard (AES-256) keys.

13. The computer-implemented method of claim 7 , further comprising:
determining a customer key in the list of customer keys is marked for shredding;
in response to determining the customer key is marked to shred, skipping an encryption process for the customer key; and
determining whether there are additional keys encrypted under the old domain key.

14. The computer-implemented method of claim 7 , further comprising:
decrypting the customer key encrypted under the old domain key; and
in response to the decryption of the at least one customer key, re-encrypting the customer key under the new domain key.

15. The computer-implemented method of claim 7 , wherein storing the re-encrypted at least one customer key comprises storing the re-encrypted at least one customer key in an encrypted key repository.

16. A non-transitory computer-readable storage medium storing thereon executable instructions that, as a result of being executed by one or more processors of a computer system, cause the computer system to:
add a new domain key to a cryptographic domain;
obtain a list of customer keys encrypted under an old domain key;
for at least one customer key in the list of customer keys:
determine the at least one customer key is not marked to shred; and
based on the at least one customer key being not marked to shred, further cause the computer system to:
transmit the at least one customer key encrypted under the old domain key to a security module;
re-encrypt, by the security module, the at least one customer key under the new domain key, the re-encrypted customer key usable by the security module to perform one or more cryptographic operations; and
store the at least one re-encrypted customer key;

Assignees

• Amazon Tech Inc

Inventors

• Roth Gregory Branchek
• Wren Matthew James
• Brandwine Eric Jason
• Pratt Brian Irl

Classifications

• H04L63/0807

  using tickets, e.g. Kerberos (cryptographic mechanisms or cryptographic arrangements for entity authentication using tickets or tokens H04L9/3213) · CPC title

• H04L63/0435

  wherein the sending and receiving network entities apply symmetric encryption, i.e. same key used for encryption and decryption (cryptographic mechanisms or cryptographic arrangements for symmetric key encryption H04L9/06) · CPC title

• H04L9/3247

  involving digital signatures · CPC title

• H04L9/16

  the keys or algorithms being changed during operation · CPC title

• H04L9/083

  involving central third party, e.g. key distribution center [KDC] or trusted third party [TTP] · CPC title