Digital currency minting in a system of network nodes implementing a distributed ledger

A method comprising:

• generating, at a first computing device at a financial institution, a currency request indicating a request for additional digital currency to be minted;
• applying, at the first computing device at the financial institution, at least one first-level signature to the currency request using at least one first-level private key, wherein the at least one first-level private key is part of a plurality of first-level private keys provided to a first set of first-level agents of the financial institution, wherein each first-level private key has a corresponding first-level public key in a plurality of first-level public keys;
• transmitting, from the first computing device to a second computing device at a currency management department, the currency request with the applied at least one first-level signature;
• receiving, from the first computing device at the second computing device, the currency request with the applied at least one first-level signature;
• generating, at the second computing device at the currency management department, a minting request from the currency request and the at least one first-level signature;
• applying, at the second computing device at the currency management department, at least one second-level signature to the minting request using at least one second-level private key to generate a signed minting request, wherein the at least one second-level private key is part of a plurality of second-level private keys provided to a second set of second-level agents of the currency management department, wherein each second-level private key has a corresponding second-level public key in a plurality of second-level public keys;
• transmitting, from the second computing device to a third computing device at a director's office, the signed minting request;
• receiving, from the second computing device at the third computing device, the signed minting request;
• applying, at the third computing device at the director's office, at least one third-level signature to the signed minting request using at least one third-level private key to generate a second signed minting request, wherein the at least one third-level private key is part of a plurality of third-level private keys provided to a third set of third-level agents of the director's office, wherein the first-level agents of the financial institution are different agents than the second-level agents of the currency management department and the third-level agents of the director's office, wherein each third-level private key has a corresponding third-level public key in a plurality of third-level public keys;
• transmitting, from the third computing device to at least one network node of a plurality of network nodes, the second signed minting request;
• receiving, from the third computing device at the at least one network node of the plurality of network nodes, the second sinned minting request;
• attempting verifying, by the at least one network node of the plurality of network nodes implementing a distributed ledger, the at least one first-level signature against the plurality of first-level public keys until at least one first-level public key corresponding to the at least one first-level private key is successfully verified or all first-level public keys have been tried, wherein the plurality of network nodes does not include the first computing device, the second computing device, and the third computing device;
• attempting verifying, by the at least one network node of the plurality of network nodes, the at least one second-level signature against the plurality of second-level public keys until at least one second-level public key corresponding to the at least one second-level private key is successfully verified or all second-level public keys have been tried;
• attempting verifying, by the at least one network node of the plurality of network nodes, the at least one third-level signature against the plurality of third-level public keys until at least one third-level public key corresponding to the at least one third-level private key is successfully verified or all third-level public keys have been tried;
• and
• minting, by the at least one network node of the plurality of network nodes, the additional digital currency only after the at least one first-level signature, the at least one second-level signature, and the at least one third-level signature are successfully verified.