US 12,243,057 B2
Offline storage system and method of use
Philip Martin, San Francisco, CA (US); Julian Borrey, San Francisco, CA (US); Yolanda Liu, San Francisco, CA (US); Zachary Blacher, San Francisco, CA (US); and Robert John Kearney, San Francisco, CA (US)
Assigned to Coinbase, Inc., Oakland, CA (US)
Appl. No. 17/044,121
Filed by Coinbase, Inc., San Francisco, CA (US)
PCT Filed Apr. 17, 2019, PCT No. PCT/US2019/027857
§ 371(c)(1), (2) Date Sep. 30, 2020,
PCT Pub. No. WO2019/204426, PCT Pub. Date Oct. 24, 2019.
Claims priority of provisional application 62/687,157, filed on Jun. 19, 2018.
Claims priority of provisional application 62/658,856, filed on Apr. 17, 2018.
Prior Publication US 2021/0019971 A1, Jan. 21, 2021
Int. Cl. G06Q 20/40 (2012.01); H04L 9/00 (2022.01); H04L 9/06 (2006.01); H04L 9/08 (2006.01); H04L 9/14 (2006.01); H04L 9/30 (2006.01)
CPC G06Q 20/401 (2013.01) [H04L 9/0637 (2013.01); H04L 9/0825 (2013.01); H04L 9/085 (2013.01); H04L 9/14 (2013.01); H04L 9/3073 (2013.01); H04L 9/50 (2022.05); G06Q 2220/00 (2013.01); H04L 2209/56 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A system for facilitating offline storage of a cryptocurrency key, the system comprising:
one or more processors programmed with instructions that, when executed by the one or more processors, cause operations comprising:
generating a symmetric-encryption ciphertext from a cryptocurrency private key by encrypting the cryptocurrency private key with a symmetric encryption key;
performing sharding of the symmetric-encryption ciphertext into key shards such that only a threshold number of the key shards is required for reconstructing the symmetric-encryption ciphertext, the threshold number being less than an overall number of the key shards derived from the sharding;
generating asymmetric-encryption shard ciphertexts from the key shards by encrypting the key shards with asymmetric encryption keys associated with the key shards, wherein generating the asymmetric-encryption shard ciphertexts from the key shards comprises:
determining, based on geographic locations associated with respective entities, a subset of entities of an entity set to respectively control regeneration of the key shards from the asymmetric-encryption shard ciphertexts such that the geographic locations are separated from one another by a threshold distance; and
using, based on the determination of the subset of entities, a first public key associated with a first entity of the subset of entities as one of the asymmetric encryption keys to encrypt at least one key shard of the key shards; and
causing storage of representations of the asymmetric-encryption shard ciphertexts in an offline computer storage system.