Key rotation techniques

Patent metadata

Field	Value
Publication number	US-9608813-B1
Application number	US-201313916999-A
Country	US
Kind code	B1
Filing date	Jun 13, 2013
Priority date	Jun 13, 2013
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A plurality of devices have common access to a cryptographic key. The cryptographic key is rotated by providing the devices simultaneous access to both the cryptographic key and a new cryptographic key and then revoking access to the cryptographic key. Keys stored externally and encrypted under the cryptographic key can be reencrypted under the new cryptographic key. Keys intended for electronic shredding can be left encrypted under the old cryptographic key.

First claim

What is claimed is:

1. A computer-implemented method, comprising:
under the control of one or more computer systems having executable instructions,
receiving a first request to electronically shred a first subset of a plurality of customer keys encrypted under a first cryptographic key;
performing a first process that results in each security module in a plurality of security modules being able to perform cryptographic operations with a customer key of the plurality of customer keys regardless of whether the customer key is encrypted using the first cryptographic key or a second cryptographic key at least by:
submitting a second request to a selected security module of the plurality of security modules;
receiving, from the selected security module, a response to the second request that includes the second cryptographic key, in a form of an encrypted second cryptographic key, encrypted in a manner decryptable by the plurality of security modules; and
providing at least the encrypted second cryptographic key to each other security module from the plurality of security modules;

for each customer key of a second subset of the plurality of customer keys encrypted under the first cryptographic key, the second subset being disjoint from the first subset as a result of having received the first request:
accessing, from a data storage system, the customer key;
instructing a security module from the plurality of security modules to:
use the first cryptographic key to decrypt the customer key to form a decrypted customer key;
use the second cryptographic key to encrypt the decrypted customer key; and
provide the customer key encrypted under the second cryptographic key; and

storing the customer key encrypted under the second cryptographic key in the data storage system; and
at a time after each customer key of the plurality of customer keys is encrypted under the second cryptographic key and stored in the data storage system:
determining that the first process was successful; and
performing a second process that results in each security module in the plurality of security modules losing access to the first cryptographic key but maintaining access to the second cryptographic key.

2. The computer-implemented method of claim 1 , further comprising selecting the second subset of the plurality of customer keys by excluding, from the plurality of customer keys, the first subset of the plurality of customer keys.

3. The computer-implemented method of claim 1 , further comprising, causing the security modules to use at least a third subset of the plurality of customer keys to perform cryptographic operations as a service to a customer of the service.

4. The computer-implemented method of claim 1 , wherein the first request is received in accordance with a rotation schedule for the plurality of customer keys.

5. The computer-implemented method of claim 1 , further comprising:
associating, for one or more customer keys outside of the plurality of customer keys, the one or more customer keys with a first status indicating pending electronic shredding; and
associating, as a result of the plurality of security modules losing access to the first cryptographic key, the one or more customer keys with a second status indicating completed electronic shredding.

6. The computer-implemented method of claim 1 , wherein being able to perform cryptographic operations with the customer key regardless of whether the customer key is encrypted using the first cryptographic key or the second cryptographic key includes being able to select between the first cryptographic key and the second cryptographic key based at least in part on an identifier associated with the customer key provided to the security module.

7. A computer-implemented method, comprising:
under the control of one or more computer systems having executable instructions,
selecting a subset of data objects from a set of data objects encrypted under a first cryptographic key;
providing, to a plurality of devices, access to both a first cryptographic key and a second cryptographic key such that the plurality of devices are able, in response to receiving a first request, to utilize either the first cryptographic key or the second cryptographic key to perform a cryptographic operation, at least by:
submitting a second request to a selected device of the plurality of devices;
receiving, from the selected device, a response to the second request that includes the second cryptographic key, in a form of an encrypted second cryptographic key, encrypted in a manner decryptable by the plurality of devices; and
providing at least the encrypted second cryptographic key to each other device from the plurality of devices; and

for each data object of the subset of data objects encrypted under the first cryptographic key:
causing a device from the plurality of devices to decrypt the data object using the first cryptographic key;
causing the device to encrypt the data object under the second cryptographic key; and
at a time after each data object of the subset of data objects is encrypted under the second cryptographic key:
determining that each security module in the plurality of devices has access to the second cryptographic key; and
causing each security module in the plurality of devices to lose access to the first cryptographic key but maintain access to the second cryptographic key.

8. The computer-implemented method of claim 7 , wherein:
the subset of data objects is a first subset;
the one or more computer systems are hosted by a service provider; and
selecting the subset of data objects is a result of having received, from a customer of the service provider on behalf of whom the set of data objects are managed by the service provider, a request to electronically shred a second subset of the set of data objects that is disjoint from the first subset.

9. The computer-implemented method of claim 7 , wherein:
the one or more computer systems are hosted by a service provider; and
the subset of data objects comprises cryptographic keys managed on behalf of customers of the service provider.

10. The computer-implemented method of claim 7 , wherein selecting the subset of data objects is based at least in part on the subset of data objects lacking an association with information indicating an instruction for electronically shredding.

11. The computer-implemented method of claim 7 , wherein the plurality of devices are security modules.

12. The computer-implemented method of claim 7 , wherein the data objects are cryptographic keys used by the devices to perform cryptographic operations.

13. The computer-implemented method of claim 7 , wherein:
the second request further includes the first cryptographic key;
the response to the second request further includes an encrypted first cryptographic key; and
the instructions that provide the encrypted second cryptographic key include instructions to provide the encrypted first cryptographic key to each other device of the plurality of devices.

14. A system, comprising:
one or more processors; and
memory including instructions that, as a result of execution by the one or more processors, cause the system to:
store data objects usable by a plurality of devices in providing a service, the data objects encrypted under a first cryptographic key;
cause the plurality of devices to have simultaneous access to the first cryptographic key and a second cryptographic key such that the plurality of devices are able, in response to receiving a first request to access a data object, to utilize either the first cryptographic key or the seco

Assignees

• Amazon Tech Inc

Inventors

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

Classifications

• H04L9/083

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

• H04L9/14

  using a plurality of keys or algorithms · CPC title

• H04L9/0822

  using key encryption key · CPC title

• H04L9/16

  the keys or algorithms being changed during operation · CPC title

• H04L9/0825

  using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates · CPC title