US 12,452,050 B2
Method for protecting payload data
Davide Lenzarini, Thalwil (CH); Michele LaManna, Pisa (IT); Carlo Vallati, Pisa (IT); Riccardo Xefraj, Pisa (IT); and Pericle Perazzo, Pisa (IT)
Assigned to u-blox AG, Thalwil (CH)
Filed by u-blox AG, Thalwil (CH)
Filed on Jul. 21, 2023, as Appl. No. 18/356,605.
Claims priority of application No. 22186471 (EP), filed on Jul. 22, 2022.
Prior Publication US 2024/0031144 A1, Jan. 25, 2024
Int. Cl. H04L 9/40 (2022.01); H04L 9/08 (2006.01); H04L 9/30 (2006.01)
CPC H04L 9/0869 (2013.01) [H04L 9/30 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for protecting payload data transmitted via a one-to-many communication channel from a provider device to at least one receiver device, the method comprising:
generating a public key set (PK) supporting asymmetric bilinear pairings for a predefined security level based on a first generator (P1) selected from a first cyclic group (G1), on a second generator (P2) selected from a second cyclic group (G2) different to the first cyclic group (G1), on a first random number (α) and on a second random number (Υ), wherein a number of elements of the public key set (PK) depends on a predefined number (n) of consumers;
generating a number of receiver device keys (DKi) based on the public key set (PK), on the second random number (Υ) and on the predefined number (n) of consumers, wherein the number (i) of receiver device keys (DKi) is equal to or smaller than the predefined number (n) of consumers and wherein a size of each receiver device key of the receiver device keys (DKi) is independent of the number (n) of consumers;
distributing, via a secure communication channel, the receiver device keys (DKi) to respective devices including the at least one receiver device;
generating a provider key (K) based on the public key set (PK), on an encryption random number (t), on the first random number (α) and on the predefined number (n) of consumers and storing the provider key (K) in the provider device;
generating an envelope (ENV) based on the public key set (PK), on the encryption random number (t) and on the predefined number (n) of consumers and storing the envelope (ENV) in the provider device and distributing, by the provider device via the one-to-many communication channel, the envelope (ENV) to the respective devices including the at least one receiver device;
generating, by the at least one receiver device, a respective receiver key, which corresponds to the provider key (K), based on the distributed envelope (ENV) and the receiver device keys received by the at least one receiver device, respectively;
performing at least one of encrypting or signing, by the provider device, the payload data employing the provider key (K) for producing protected payload data;
distributing, by the provider device via the one-to-many communication channel, the protected payload data to the respective devices including the at least one receiver device; and
processing, by the least one receiver device, the protected payload data employing the respective receiver key, wherein the processing includes at least one of decrypting or authenticating.