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US 8,555,059 B2Granted
Secure local update of content management software
AssigneeMicrosoft Corporation
InventorsAlexander McKelvey, Clifford P. Strom, Quintin S. Burns
Life of this patent
Estimating the term…
Abstract
This document describes tools that enable a computing device to receive an update to content management software. The tools also enable the computing device to generate new public and private keys without the use of a key server.
Claims20
A computer-implemented method comprising:
- receiving a software update at a computing device having an existing software application, the existing software application having an historic public/private key pair including an historic private key and an historic public key, the historic private key usable by the existing software application to access historic protected content, the historic protected content previously protected using the historic public key and the existing software application;
- and
- applying the software update to the existing software application to provide an updated software application, applying the software update including:
- retaining the historic private key for use by the updated software application to access the historic protected content, the historic private key not usable to access new protected content, the new protected content protected by a new public key and the updated software application;
- generating a new public/private key pair locally at the computing device, the new public/private key pair including the new public key and a new private key, the new public key usable to protect content to provide the new protected content, the new private key usable by the updated software application to access the new protected content;
- encrypting the new private key at the computing device using a symmetric key included in the software update to create an encrypted private key thereby preventing the new private key from being determined by unauthorized software applications or users;
- storing the encrypted private key within a key file located at the computing device, the updated software application capable of accessing the new private key by decrypting the encrypted private key using the symmetric key;
- removing the historic public key in the historic public/private key pair from local storage at the computing device;
- and in an event that one or more retained historic private keys are unused, removing from the local storage at the computing device:
- the one or more retained historic private keys that are unused;
- and one or more retained historic symmetric keys that are usable to generate the one or more retained historic private keys that are unused.
8 more elements
One or more computer-readable storage memory having stored thereon computer-executable instructions that, if executed by a computing device, cause the computing device to perform a method comprising:
- receiving a software update at the computing device, the computing device including an existing software application having an historic public/private key pair including an historic private key and an historic public key, the historic private key usable by the existing software application to access historic protected content, the historic protected content previously protected using the historic public key and the existing software application;
- and
- applying the software update to the existing software application to provide an updated software application, applying the software update including:
- retaining the historic private key for use by the updated software application to access the historic protected content, the historic private key not usable to access new protected content, the new protected content protected by a new public key and the updated software application;
- generating a new public/private key pair locally at the computing device, the new public/private key pair including the new public key and a new private key, the new public key usable to protect content to provide the new protected content, the new private key usable by the updated software application to access the new protected content;
- encrypting the new private key at the computing device using a symmetric key included in the software update to create an encrypted private key;
- storing the encrypted private key within a key file located at the computing device, the updated software application capable of accessing the new private key by decrypting the encrypted private key using the symmetric key;
- removing the historic public key in the historic public/private key pair from local storage at the computing device;
- and
- in an event that one or more unused historic private keys are locally stored at the computing device, removing from local storage at the computing device:
- one or more unused private keys;
- and
- one or more retained historic symmetric keys that are usable to generate the one or more unused private keys.
10 more elements
Dependencies are inferred from the claim text.