Patent ID: 7028886

Claim:
A method for detecting duplicate commercial paper transactions comprising: identifying a check identification code from a commercial paper transaction, the check identification code comprising a plurality of fields; determining a first hash value based on at least a portion of the plurality of fields; communicating the first hash value to a repository storing a plurality of hash values, each hash value associated with an authenticated commercial paper transaction; if the repository does not include the first hash value as one of the plurality of hash values, authenticating the commercial paper transaction; if the repository includes the first hash value as one of the plurality of hash values, identifying the commercial paper transaction as a duplicate; identifying an updated check identification code based on a bank's processing of the authenticated transaction; determining a second hash value based on the updated check identification code; communicating the second hash value to the repository; if the repository does not include the second hash value as one of the plurality of hash values, authenticating the processed commercial paper transaction; and if the repository includes the second hash value as one of the plurality of hash values, identifying the processed commercial paper transaction as a duplicate.