Entitlement management message epoch as an external trusted time source
US11025424B2 · kind B2 · utility
1Cited by
3References
20Claims
0Family size
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Key dates
| Filing date | Apr 26, 2019 |
| Grant date | Jun 1, 2021 |
| Priority date | — |
| Expiry date | Dec 5, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/6543
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An external trusted time source is implemented over a network for conditional access system (CAS)/digital rights management (DRM) client devices. A client device includes untrusted software and a trusted execution environment (TEE) for processing an entitlement management message (EMM) that includes an epoch sequence number (ESN) transmitted from an EMM server using a first network connection. A remaining client key set (CKS) lifetime value is stored and updated in the TEE based on the ESN processed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.