Patent ID: 11870913
Assignee: THALES DIS FRANCE SAS
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 9:
10. A client device comprising:
a processor to generate a digital signature of an input message (M) based on a secret key (dA), and
a memory for temporary storage of a first set and a second set of precomputed data during an execution of said processor,
wherein said processor:
generates (S1) a private element (k), homomorphically encrypted, by combining homomorphically encrypted private element parts selected in the first set (ki);
generates (S2) a public element (Q) by combining public element parts (Qi) selected from the second set and paired with the private element parts selected in the first set;

generates (S3) a first part of the digital signature (r) from said public element; and
generates (S4) a second part of the digital signature of the input message (M), the secret key (dA), the public element and the private element,
wherein said private element is a discrete logarithm of said public element,
wherein said selection of the public and private element parts depends on the input message.