US 12,348,652 B2
Key derivation method
Chloe Tartan, London (GB); Michaella Pettit, London (GB); Alessio Pagani, London (GB); and Wei Zhang, London (GB)
Assigned to nChain Licensing AG, Zug (CH)
Appl. No. 18/034,340
Filed by nChain Licensing AG, Zug (CH)
PCT Filed Oct. 15, 2021, PCT No. PCT/EP2021/078601
§ 371(c)(1), (2) Date Apr. 27, 2023,
PCT Pub. No. WO2022/100958, PCT Pub. Date May 19, 2022.
Claims priority of application No. 2017904 (GB), filed on Nov. 13, 2020.
Prior Publication US 2023/0396450 A1, Dec. 7, 2023
Int. Cl. H04L 29/06 (2006.01); H04L 9/00 (2022.01); H04L 9/08 (2006.01); H04L 9/32 (2006.01)
CPC H04L 9/3268 (2013.01) [H04L 9/0866 (2013.01); H04L 9/3242 (2013.01); H04L 9/3265 (2013.01); H04L 9/50 (2022.05)] 20 Claims
OG exemplary drawing
 
1. A computer-implemented method of deriving keys of a hierarchical key structure, wherein the key structure comprising a hierarchy of levels, the hierarchy of levels comprising a master level and one or more child levels, wherein the master level comprises a master key, and wherein each child level comprises one or more child keys, each respective child key of a given level being linked to one key of a preceding level, wherein that one key of the preceding level is a respective parent key of the respective child key, and wherein the method is performed by a first party and comprises:
generating a target index of a target child key, wherein the target index is generated based on a first result of inputting at least a target message to a first hash function; and
deriving the target child key of a level in the hierarchy based on a) a parent key of a preceding level in the hierarchy, and b) a second result of inputting at least i) the parent key, and ii) the target index, to a second hash function.