Invention Grant
- Patent Title: Cryptographic protection of usage restrictions in electronic devices
- Patent Title (中): 电子设备使用限制的密码保护
-
Application No.: US12351643Application Date: 2009-01-09
-
Publication No.: US08225110B2Publication Date: 2012-07-17
- Inventor: Per Stáhl , Chris Loreskär , Bernard Smeets
- Applicant: Per Stáhl , Chris Loreskär , Bernard Smeets
- Applicant Address: SE Stockholm
- Assignee: Telefonaktiebolaget LM Ericsson (publ)
- Current Assignee: Telefonaktiebolaget LM Ericsson (publ)
- Current Assignee Address: SE Stockholm
- Agency: Coats & Bennett, P.L.L.C.
- Main IPC: G06F11/30
- IPC: G06F11/30 ; G06F12/14 ; G06F7/04 ; H04K1/00 ; H04L9/00 ; G06F21/00 ; H04L9/06

Abstract:
An electronic device requires valid control keys to change any usage restriction setting. The device is provided control keys, a secret key, and a signed software object including a batch ID and a hash of the secret key. For each control key, the device generates a cryptographic footprint bound to the device and the secret key. A message authentication code (MAC) of each usage restriction setting is generated, the MAC bound to the device and a control key. To change a usage restriction, the device receives a control key, validates it against the stored footprint, changes the usage restriction settings, and generates a new usage restriction setting MAC. The control key footprints are bound to the secret key, but the device retains only a hash of the secret key.
Public/Granted literature
- US20100180130A1 Cryptographic Protection of Usage Restrictions in Electronic Devices Public/Granted day:2010-07-15
Information query