US 12,423,684 B2
Digital signature generation using a cold wallet
Jakob Illeborg Pagter, Aarhus V (DK); and Thomas Pelle Jakobsen, Marslet (DK)
Assigned to BLOCKDAEMON APS, Aarhus (DK)
Appl. No. 17/764,814
Filed by Blockdaemon ApS, Aarhus C (DK)
PCT Filed Oct. 6, 2020, PCT No. PCT/EP2020/077977
§ 371(c)(1), (2) Date Mar. 29, 2022,
PCT Pub. No. WO2021/073953, PCT Pub. Date Apr. 22, 2021.
Claims priority of application No. 19203273 (EP), filed on Oct. 15, 2019; and application No. 20151197 (EP), filed on Jan. 10, 2020.
Prior Publication US 2022/0327530 A1, Oct. 13, 2022
Int. Cl. G06Q 20/38 (2012.01); G06Q 20/36 (2012.01)
CPC G06Q 20/3825 (2013.01) [G06Q 20/3674 (2013.01); G06Q 20/3829 (2013.01); G06Q 2220/00 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method for providing a digital signature, the method comprising the steps of:
receiving by two or more nodes of a cold wallet, one or more shares of a private signature key, each node of the cold wallet thereby being in the possession of the one or more shares of the private signature key, and none of the nodes of the cold wallet being in the possession of all shares of the private signature key;
generating by each node of the cold wallet a pre-signature, based on its share(s) of the private signature key, and transmitting the pre-signature to one of two or more pre-signature nodes, in such a manner that each pre-signature node receives a pre-signature from only one of the nodes of the cold wallet;
requesting by a signing application a signature and transmitting a message to be signed to each of the pre-signature nodes;
in response to receiving the request for a signature and the message to be signed, generating by each pre-signature node a partial signature, based on its pre-signature and on the message to be signed;
transmitting by each pre-signature node its partial signature to the signing application; and
in response to receiving the partial signatures from each pre-signature node, computing by the signing application a digital signature from the received partial signatures;
wherein the step of each node of the cold wallet transmitting the pre-signature to one of the pre-signature nodes is performed using a one-way communication channel.