Patent ID: 7413119

Claim:
A transaction authorization system, comprising: an authorization engine configured to perform an analysis in relation to a received request for authorization of a current electronic payment transaction and generate an authorization output based on the analysis, a database storing a plurality of transaction records for past electronic payment transactions, wherein the authorization engine is configured to: access the database to determine one or more distribution functions based on at least some of the stored transaction records, determine one or more intermediate values in relation to the received authorization request based on the one or more distribution functions, determine a conditional probability in relation to the one or more intermediate values based on at least some of the stored transaction records, the conditional probability indicative of a probability of a particular transaction result under the condition of the one or more intermediate values, and generate the authorization output based on the determined conditional probability, wherein the authorization engine is configured to determine one or more first frequency distribution functions in relation to each of a plurality of payor account identifiers based on stored transaction records having the respective payor account identifiers, the one or more first frequency distribution functions being indicative of the frequency distribution of one or more transaction attributes of electronic payment transactions associated with a respective payor account identifier.