US 12,445,416 B2
Methods and systems for compressed encryption
Thomas Prest, Oxford (GB); Shuichi Katsumata, Tokyo (JP); and Kris Kwiatkowski, Oxford (GB)
Assigned to PQShield Ltd., Oxford (GB)
Filed by PQShield Ltd, Oxford (GB)
Filed on Oct. 4, 2022, as Appl. No. 17/937,969.
Application 17/937,969 is a continuation of application No. PCT/GB2021/050838, filed on Apr. 6, 2021.
Claims priority of application No. 2005237 (GB), filed on Apr. 8, 2020.
Prior Publication US 2023/0224281 A1, Jul. 13, 2023
Int. Cl. H04L 9/40 (2022.01); H04L 9/08 (2006.01); H04L 9/30 (2006.01)
CPC H04L 63/0428 (2013.01) [H04L 9/0869 (2013.01); H04L 9/30 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A computer-implemented method for transmitting a ciphertext comprising a plurality of encrypted parts to a plurality of users, comprising:
(a) providing a common set of system parameters for said plurality of users, which common set of system parameters includes a first parameter from a first probability distribution function;
(b) generating said plurality of encrypted parts by encrypting a plaintext using parameters unique to each user of said plurality of users that comprise respective public keys of the plurality of users and second parameters from a second probability distribution function, wherein the encrypted parts are encrypted using a lattice-based encryption scheme;
(c) generating said ciphertext comprising a part derived from said common set of system parameters and said plurality of encrypted parts; and
(d) transmitting said ciphertext to said plurality of users, wherein said ciphertext is decryptable at least in part using said parameters unique to each user of said plurality of users.