Integrated circuit with secure metadata store
View Patent ↗A semiconductor integrated circuit for processing content data by encrypting or decrypting the data has one or more inputs to received content and metadata. A metadata store comprises two portions, a first portion for storing metadata itself and a second portion for storing an address of locations of bitfields of metadata. This arrangement allows for efficient storage of the metadata but requires certain rules to ensure that bitfields of metadata cannot be stored and used with anything other than the content with which the metadata is associated.
1. A semiconductor integrated circuit for operating cryptographic processes on content data, comprising:
one or more inputs arranged to receive content data and metadata, wherein the metadata comprises instructions allowing the content data to be encrypted or decrypted, the metadata including packages each comprising a plurality of bitfields; and
a metadata store arranged to receive the plurality of metadata bitfields for use by the cryptographic processes;
wherein the metadata store comprises an address portion and a data portion, wherein the data portion is arranged to store exclusively the metadata bitfields and the address portion is arranged to store exclusively addresses indicating locations of the metadata bitfields within the data portion.
2. A semiconductor integrated circuit according to claim 1 , wherein the data portion comprises a memory of width substantially one bitfield and depth appropriate to the number of bitfields to be stored.
3. A semiconductor integrated circuit to claim 1 , further comprising a controller structured to store only selected bitfields in the data portion.
4. A semiconductor integrated circuit according to claim 1 , further comprising a controller structured to store only selected bitfields of each package in the data portion.
5. A semiconductor integrated circuit according to claim 1 , wherein at least some of the bitfields are null, the integrated circuit further comprising a controller structured to not store the null bitfields in the data portion.
6. A semiconductor integrated circuit according to claim 1 , further comprising a controller structured, such that if one bitfield of a given one of the packages in the data portion is overwritten, then the controller renders unusable other bitfields of the given one of the packages.
7. A semiconductor integrated circuit according to claim 6 , wherein the other bitfields are rendered unusable by being marked as invalid in the data portion.
8. A semiconductor integrated circuit according to claim 6 , wherein the other bitfields are rendered unusable by their addresses being marked as invalid in the address portion.
9. A semiconductor integrated circuit according to claim 1 , wherein each metadata package is related to specific content data.
10. A semiconductor integrated circuit according to claim 1 , wherein the address portion is indexed using information in the content data.
11. A content data processing device for operating cryptographic processes on content data, comprising:
one or more inputs arranged to receive content data and metadata, wherein the metadata comprises instructions allowing the content data to be encrypted or decrypted, the metadata including packages each comprising a plurality of bitfields; and
a metadata store arranged to receive the plurality of metadata bitfields for use by the cryptographic processes;
wherein the metadata store comprises an address portion and a data portion, wherein the data portion is arranged to store exclusively the metadata bitfields and the address portion is arranged to store exclusively addresses indicating locations of the metadata bitfields within the data portion.
12. A content data processing device according to claim 11 , wherein the content data processing device is a set top box.
13. A content data processing device according to claim 11 , wherein the data portion comprises a memory of width substantially one bitfield and depth appropriate to the number of bitfields to be stored.
14. A content data processing device to claim 11 , further comprising a controller structured to store only selected bitfields in the data portion.
15. A content data processing device according to claim 11 , further comprising a controller structured to store only selected bitfields of each package in the data portion.
16. A content data processing device according to claim 11 , wherein at least some of the bitfields are null, the integrated circuit further comprising a controller structured to not store the null bitfields in the data portion.
17. A content data processing device according to claim 11 , further comprising a controller structured, such that if one bitfield of a given one of the packages in the data portion is overwritten, then the controller renders unusable other bitfields of the given one of the packages.
18. A content data processing device according to claim 17 , wherein the other bitfields are rendered unusable by being marked as invalid in the data portion.
19. A content data processing device according to claim 17 , wherein the other bitfields are rendered unusable by their addresses being marked as invalid in the address portion.
20. A method, comprising:
receiving metadata corresponding to content data, wherein the metadata comprises instructions allowing the content data to be encrypted or decrypted, the metadata including packages each comprising a plurality of metadata bitfields; and
storing at least some of the metadata bitfields in a data portion of a metadata store;
excluding storing in the data portion of the metadata store items other than the metadata bitfields;
storing, in an address portion of the metadata store, addresses of the at least some of the metadata bitfields indicating locations of the metadata bitfields; and
excluding storing items other than the addresses of the at least some of the metadata bitfields.
21. A method according to claim 20 , wherein storing at least some of the metadata bitfields includes storing only selected bitfields in the data portion.
22. A method according to claim 20 , wherein storing at least some of the metadata bitfields includes storing only selected bitfields of each package in the data portion.
23. A method according to claim 20 , wherein at least some of the bitfields are null, wherein storing at least some of the metadata bitfields includes preventing storage of the null bitfields in the data portion.
24. A method according to claim 20 , further comprising:
overwriting one bitfield of a given one of the packages in the data portion; and
rendering unusable other bitfields of the given one of the packages.
25. A method according to claim 24 , wherein the rendering unusable step includes rendering unusable the other bitfields by marking invalid the other bitfields in the data portion.
26. A method according to claim 24 , wherein the rendering unusable step includes rendering unusable the other bitfields by marking their addresses as invalid in the address portion.