US 12,294,661 B2
Personal device security using cryptocurrency wallets
Craig Steven Wright, London (GB); and Stephane Savanah, London (GB)
Assigned to NCHAIN LICENSING AG, Zug (CH)
Filed by nChain Holdings Limited, St. John's (AG)
Filed on Jun. 6, 2022, as Appl. No. 17/833,433.
Application 17/833,433 is a continuation of application No. 16/926,583, filed on Jul. 10, 2020, granted, now 11,356,280.
Application 16/926,583 is a continuation of application No. 16/079,082, granted, now 10,715,336, issued on Jul. 14, 2020, previously published as PCT/IB2017/050815, filed on Feb. 14, 2017.
Claims priority of application No. 1603117 (GB), filed on Feb. 23, 2016; application No. 1603122 (GB), filed on Feb. 23, 2016; and application No. 1619301 (GB), filed on Nov. 15, 2016.
Prior Publication US 2023/0107243 A1, Apr. 6, 2023
Int. Cl. H04L 9/32 (2006.01); H04L 9/08 (2006.01); H04L 9/30 (2006.01); H04W 12/02 (2009.01); H04W 12/03 (2021.01); H04W 84/18 (2009.01)
CPC H04L 9/3252 (2013.01) [H04L 9/0825 (2013.01); H04L 9/0841 (2013.01); H04L 9/085 (2013.01); H04L 9/0891 (2013.01); H04L 9/3066 (2013.01); H04W 12/02 (2013.01); H04W 12/03 (2021.01); H04L 2209/56 (2013.01); H04W 84/18 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A computer implemented method of determining a common secret at an electronic device (S), the electronic device being configured to communicate with a key device (C), wherein the electronic device is further associated with a first asymmetric cryptography pair having a first electronic device private key (V1S) and a first electronic device public key (P1S), and the key device is associated with a second asymmetric cryptography pair having a first key device private key (V1C) and a first key device public key (P1C), the method comprising:
determining, at the electronic device, a deterministic key (DK);
determining, at the electronic device, a second electronic device private key (V2S) based on at least the first electronic device private key (V1S) and the deterministic key (DK);
determining, at the electronic device, a second key device public key (P2C) based on at least the first key device public key (P1C) and the deterministic key (DK);
determining a secret based on at least the second electronic device private key (V2S) and the second key device public key (P2C);
encrypting data at the electronic device using the determined secret or an encryption key that is based on the determined secret;
sending information indicative of the deterministic key (DK) to the key device;
determining, at the electronic device, an updated second electronic device private key (V2S) based on at least the first electronic device private key (V1S) and the deterministic key (DK);
determining, at the electronic device, an updated second key device public key (P2C) based on at least the first key device public key (P1C) and the deterministic key (DK);
determining an updated secret based on at least the updated second electronic device private key (V2S) and the updated second key device public key (P2C); and
encrypting data at the electronic device using the determined updated secret or an encryption key that is based on the determined updated secret.