US 12,388,623 B2
Method for processing encrypted data
George French, London (GB)
Assigned to Barclays Execution Services Limited, London (GB)
Appl. No. 18/035,265
Filed by Barclays Execution Services Limited, London (GB)
PCT Filed Dec. 18, 2020, PCT No. PCT/EP2020/087139
§ 371(c)(1), (2) Date May 3, 2023,
PCT Pub. No. WO2022/096141, PCT Pub. Date May 12, 2022.
Claims priority of application No. 20206297 (EP), filed on Nov. 6, 2020.
Prior Publication US 2023/0403134 A1, Dec. 14, 2023
Int. Cl. H04L 29/06 (2006.01); H04L 9/06 (2006.01); H04L 9/08 (2006.01); H04L 9/14 (2006.01)
CPC H04L 9/0637 (2013.01) [H04L 9/0819 (2013.01); H04L 9/14 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A computer-implemented method for processing a first ciphertext, C1, wherein the first ciphertext is data encrypted with a plurality of keys, k1 . . . kn, the method comprising:
receiving a first key, k1, wherein the first key is one of the plurality of keys;
receiving the first ciphertext, C1;
performing an exclusive OR operation on the first ciphertext, C1, and the first key, k1, to produce a second ciphertext, C2, such that the second ciphertext, C2, is the data encrypted with the plurality of keys, k2 . . . kn, and not with the first key, k1;
receiving a further key, k2;
receiving the second ciphertext, C2; and
after a predetermined time period equal to or less than a crypto period of the keys in the plurality of keys, performing an exclusive OR operation on the second ciphertext, C2, and the further key, k2, to produce a third ciphertext, C3, such that the third ciphertext, C3, is the data encrypted with the plurality of keys, k3 . . . kn, and not with the first and further keys k1, k2.