Abstract: A system for generating authorization codes, such as personal identification numbers, at the point of distribution of certificates of value on which the authorization codes are to be printed or otherwise encoded. Because the authorization codes are generated in real time, there is no need to store and safeguard an inventory of preprinted certificates, or even an inventory of activated authorization codes. The principles of the invention apply both to systems for generating incentive award certificates and to systems for generating purchased certificates of value. The incentive awards or certificates of value are tokens of prepayment for a service, such as long-distance telephone service or other service. The authorization codes generated for inclusion with the value certificates are unique and seemingly random. They are generated by taking a non-random unique code, such as a sequence code, and encrypting it to obtain seemingly random, but unique, authorization codes.

Abstract: A system for generating authorization codes, such as personal identification numbers, at the point of distribution of certificates of value on which the authorization codes are to be printed or otherwise encoded. Because the authorization codes are generated in real time, there is no need to store and safeguard an inventory of preprinted certificates, or even an inventory of activated authorization codes. The principles of the invention apply both to systems for generating incentive award certificates and to systems for generating purchased certificates of value. The incentive awards or certificates of value are tokens of prepayment for a service, such as long-distance telephone service or other service. The authorization codes generated for inclusion with the value certificates are unique and seemingly random. They are generated by taking a non-random unique code, such as a sequence code, and encrypting it to obtain seemingly random, but unique, authorization codes.