US 12,481,792 B2
Method for processing digital information
Karine Villegas, Cheseaux-sur-Lausanne (CH); Roan Hautier, Cheseaux-sur-Lausanne (CH); Pascal Fuchs, Cheseaux-sur-Lausanne (CH); and Fabien Gremaud, Cheseaux-sur-Lausanne (CH)
Assigned to NAGRAVISION SARL, Cheseaux-sur-Lausanne (CH)
Appl. No. 17/996,883
Filed by NAGRAVISION SARL, Cheseaux-sur-Lausanne (CH)
PCT Filed Apr. 19, 2021, PCT No. PCT/EP2021/060019
§ 371(c)(1), (2) Date Oct. 21, 2022,
PCT Pub. No. WO2021/213951, PCT Pub. Date Oct. 28, 2021.
Claims priority of application No. 20171173 (EP), filed on Apr. 23, 2020.
Prior Publication US 2023/0153470 A1, May 18, 2023
Int. Cl. G06F 21/64 (2013.01); H04L 9/32 (2006.01)
CPC G06F 21/64 (2013.01) [H04L 9/3247 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A method for processing digital information, performed by a processing device, said digital information being stored in a plurality of segments in an external memory, the method comprising:
loading a first integrity table containing a plurality of first integrity elements respectively authenticating the plurality of segments of digital information, and an associated digital signature of said plurality of first integrity elements, from the external memory;
verifying the digital signature associated with the first integrity table,
after loading the first integrity table and verifying the associated digital signature, loading encrypted segments of digital information from the external memory to the processing device;
loading separately integrity data of the segments of digital information from the external memory, wherein the integrity data of each segment of digital information includes a first integrity element encrypted and a second integrity element authenticating encrypted data resulting from an encryption of said segment of digital information concatenated with said first integrity element; and, for each segment of digital information:
concatenating the encrypted segment of digital information that has been loaded and the corresponding integrity data loaded separately;
verifying the integrity of the encrypted segment of digital information concatenated with the first integrity element encrypted using the second integrity element;
decrypting the segment of digital information and the first integrity element and outputting the segment of digital information and the first integrity element concatenated together;
verifying the integrity of the segment of digital information using the concatenated first integrity element;
checking that the first integrity element matches a corresponding first integrity element in the first integrity table, an authenticity of the segment being indirectly verified by the verification of the digital signature associated with the first integrity table; and
processing the segment of digital information.