US 12,346,438 B2
Method for securely processing digital information in a secure element
Karine Villegas, Cheseaux-sur-Lausanne (CH); and Roan Hautier, Cheseaux-sur-Lausanne (CH)
Assigned to Nagravision Sarl, Cheseaux-sur-Lausanne (CH)
Appl. No. 17/907,378
Filed by Nagravision Sarl, Cheseaux-sur-Lausanne (CH)
PCT Filed Mar. 25, 2021, PCT No. PCT/EP2021/057819
§ 371(c)(1), (2) Date Sep. 26, 2022,
PCT Pub. No. WO2021/198035, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 20167097 (EP), filed on Mar. 31, 2020.
Prior Publication US 2023/0119890 A1, Apr. 20, 2023
Int. Cl. G06F 21/55 (2013.01); G06F 21/64 (2013.01); G06F 21/79 (2013.01)
CPC G06F 21/556 (2013.01) [G06F 21/64 (2013.01); G06F 21/79 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for securely processing, within a secure element, digital information, said secure element including a secure processor adapted for security-critical applications, and at least one internal memory and a code associating unit, both external to the secure processor, wherein the method provides an end-to-end security ensuring that the digital information has not been altered from storage in an external memory to processing by the secure processor, and comprises the steps, performed by the secure element:
loading the digital information from the external memory into the at least one internal memory of the secure element;
decrypting the digital information to obtain the digital information in clear and a first integrity element;
by the code associating unit, segmenting the digital information in clear into words of digital information, generating error-detection codes or error-correction codes from said words of digital information and associating said error-detection codes or error-correction codes with the corresponding words in the at least one internal memory;
verifying the integrity of the digital information in clear by calculating an integrity element based on the segmented words and comparing the calculated integrity element with the first integrity element obtained during decryption, ensuring that the digital information has not been altered before transferring;
transferring the words of digital information and the associated error-detection codes or error-correction codes from the at least one internal memory to the secure processor;
by the secure processor, verifying the words of digital information based on the associated error-detection codes or error-correction codes before processing the digital information contained in said words.