Systems, devices, and methods for detecting double signing in a one-time use signature scheme

A computer-implemented method, comprising:

• receiving a message, wherein the message comprises a signature generated using a one-time use private key of a hash-based one-time use public/private key pair;
• determining a one-time use public key of the hash-based one-time public/private key pair based on the message;
• determining that the hash-based one-time use public/private key pair was used more than once by comparing the one-time use public key to a list of public keys;
• generating an alert based on determining that the hash-based one-time use public/private key pair was used more than once;
• and
• forging, using one or more processors, a signature associated with the one-time use private key based on the message and a previous message signed using the one-time use private key.

A non-transitory computer readable storage medium comprising instructions for causing one or more processors to:

• receive a message, wherein the message comprises a signature generated using a one-time use private key of a hash-based one-time use public/private key pair;
• determine a one-time use public key of the hash-based one-time public/private key pair based on the message;
• determine that the hash-based one-time use public/private key pair was used more than once by comparing the one-time use public key to a list of public keys;
• generate an alert based on determining that the hash-based one-time use public/private key pair was used more than once;
• and
• forge a signature associated with the one-time use private key based on the message and a previous message signed using the one-time use private key.