Abstract: In certain embodiments, the use of re-usable cold storage keys to sign messages may be facilitated. In some embodiments, an offline computer system (operating within an offline computing environment) may obtain, from a removable computer-readable storage medium, signing key shards corresponding to a signing private key and a blockchain transaction to be signed, where the signing key shards satisfy a key shard threshold that is (i) a number of key shards required for reconstructing the signing private key and (ii) less than a number of key shards derived from the signing private key using a ceremony key. The offline computer system may form a ciphertext of the signing private key using the signing key shards and reconstruct the signing private key by decrypting the ciphertext using the ceremony key. The offline computer system may sign the blockchain transaction using the signing private key.

Abstract: One or more aspects described herein provide methods and systems for authoritatively confirming that a recipient is an intended recipient to receive personal data, and to securely transmit the personal data to the intended recipient, when both the sender and receiver are operating in a trustless ecosystem such as that used with blockchain technology. A computing device may receive an indication of a blockchain address used, by a sender computing device and via a blockchain, to send one or more virtual assets. The computing device may store an association between the blockchain address and the recipient. The computing device may send, to the sender computing device and in response to a query comprising the blockchain address, an indication of the recipient. The indication may be configured to cause the sender computing device to send, to the recipient, personal data associated with an owner of the one or more virtual assets.

Abstract: One or more aspects described herein provide methods and systems for authoritatively confirming that a recipient is an intended recipient to receive personal data, and to securely transmit the personal data to the intended recipient, when both the sender and receiver are operating in a trustless ecosystem such as that used with blockchain technology. A computing device may receive an indication of a blockchain address used, by a sender computing device and via a blockchain, to send one or more virtual assets. The computing device may store an association between the blockchain address and the recipient. The computing device may send, to the sender computing device and in response to a query comprising the blockchain address, an indication of the recipient. The indication may be configured to cause the sender computing device to send, to the recipient, personal data associated with an owner of the one or more virtual assets.

Abstract: One or more aspects described herein provide methods and systems for authoritatively confirming that a recipient is an intended recipient to receive personal data, and to securely transmit the personal data to the intended recipient, when both the sender and receiver are operating in a trustless ecosystem such as that used with blockchain technology. A computing device may receive an indication of a blockchain address used, by a sender computing device and via a blockchain, to send one or more virtual assets. The computing device may store an association between the blockchain address and the recipient. The computing device may send, to the sender computing device and in response to a query comprising the blockchain address, an indication of the recipient. The indication may be configured to cause the sender computing device to send, to the recipient, personal data associated with an owner of the one or more virtual assets.

Abstract: Systems and methods for signing messes using re-usable cold storage keys.

Abstract: A method of operating an access control system containing one or more hierarchies, each of the one or more hierarchies includes one or more access levels is provided. The method including: computing one or more hierarchies; and assigning a primary access level of the one or more access levels within a primary hierarchy of the one or more hierarchies to a first credential; and determining that access levels vertically below the primary access level in the primary hierarchy are implicitly assigned to the first credential when assigning the primary access level of the one or more access levels within the primary hierarchy of the one or more hierarchies to the first credential.

Abstract: A method for storing a cryptocurrency private key offline, including: encrypting the cryptocurrency private key using a primary encryption key; sharding the encrypted cryptocurrency private key into a plurality of alpha shards; generating beta shards by encrypting the alpha shards with secondary encryption keys; and storing representations of the beta shards offline. The method can additionally or alternatively include: retrieving the representations of the beta shards from the offline storage; decrypting the beta shards into the alpha shards based on the secondary encryption keys; reconstructing the encrypted cryptocurrency private key by recombining the alpha shards; and decrypting the encrypted cryptocurrency private key with the primary encryption key.