Primary account number (pan) length issuer identifier in payment account number data field of a transaction authorization request message

Abstract

Transaction data is obtained relating to a current purchase transaction. An account indicator is retrieved. The transaction data is used to transform the account indicator. The transformed account indicator is encrypted to generate an encrypted account indicator.

What is claimed is: 
     
         1 . A computing system, comprising:
 a network interface configured to receive an authorization request message that comprises an encrypted primary account number (PAN); and   a processor configured to
 identify a decryption key for the encrypted PAN based on a PAN-length issuer identifier in the authorization request message; 
 decrypt the encrypted PAN based on the identified decryption key; 
 modify the authorization request message with the decrypted PAN; and 
 transmit the modified authorization request message with the decrypted PAN to computing system of an issuer of the PAN. 
   
     
     
         2 . The computing system of  claim 1 , wherein the network interface is configured to receive the authorization request message with the encrypted PAN from a point of sale (POS) terminal. 
     
     
         3 . The computing system of  claim 1 , wherein the encrypted PAN is stored in a separate field of the payment authorization request message with respect to the PAN-length issuer identifier. 
     
     
         4 . The computing system of  claim 1 , wherein the PAN-length issuer identifier does not identify a payment account number of a corresponding PAN. 
     
     
         5 . The computing system of  claim 1 , wherein the processor is configured to decrypt the encrypted PAN to create a token and apply a mask to the token to reveal the decrypted PAN. 
     
     
         6 . The computing system of  claim 5 , wherein the processor is further configured to read one or more transaction values from the authorization request message and generate the mask based on a predefined function applied to the one or more transaction values. 
     
     
         7 . The computing system of  claim 1 , wherein the processor is configured to read the PAN-length identifier from a field other than a payment account number field. 
     
     
         8 . A method, comprising:
 receiving an authorization request message that comprises an encrypted primary account number (PAN);   identifying a decryption key for the encrypted PAN based on a PAN-length issuer identifier in the authorization request message;   decrypting the encrypted PAN based on the identified decryption key;   modifying the authorization request message with the decrypted PAN; and   transmitting the modified authorization request message with the decrypted PAN to computing system of an issuer of the PAN.   
     
     
         9 . The method of  claim 8 , wherein the receiving comprises receiving the authorization request message with the encrypted PAN from a point of sale (POS) terminal. 
     
     
         10 . The method of  claim 8 , wherein the encrypted PAN is stored in a separate field of the payment authorization request message with respect to the PAN-length issuer identifier. 
     
     
         11 . The method of  claim 8 , wherein the PAN-length issuer identifier does not identify a payment account number of a corresponding PAN. 
     
     
         12 . The method of  claim 8 , wherein the decrypting comprises decrypting the encrypted PAN to create a token and applying a mask to the token to reveal the decrypted PAN. 
     
     
         13 . The method of  claim 12 , wherein the method further comprises reading one or more transaction values from the authorization request message and generating the mask based on a predefined function applied to the one or more transaction values. 
     
     
         14 . The method of  claim 8 , wherein the method further comprises reading the PAN-length identifier from a field other than a payment account number field. 
     
     
         15 . A non-transitory computer-readable medium comprising instructions which when executed by a processor cause a computer to perform a method comprising:
 receiving an authorization request message that comprises an encrypted primary account number (PAN);   identifying a decryption key for the encrypted PAN based on a PAN-length issuer identifier in the authorization request message;   decrypting the encrypted PAN based on the identified decryption key;   modifying the authorization request message with the decrypted PAN; and   transmitting the modified authorization request message with the decrypted PAN to computing system of an issuer of the PAN.   
     
     
         16 . The non-transitory computer-readable medium of  claim 15 , wherein the receiving comprises receiving the authorization request message with the encrypted PAN from a point of sale (POS) terminal. 
     
     
         17 . The non-transitory computer-readable medium of  claim 15 , wherein the encrypted PAN is stored in a separate field of the payment authorization request message with respect to the PAN-length issuer identifier. 
     
     
         18 . The non-transitory computer-readable medium of  claim 15 , wherein the PAN-length issuer identifier does not identify a payment account number of a corresponding PAN. 
     
     
         19 . The non-transitory computer-readable medium of  claim 15 , wherein the decrypting comprises decrypting the encrypted PAN to create a token and applying a mask to the token to reveal the decrypted PAN. 
     
     
         20 . The non-transitory computer-readable medium of  claim 19 , wherein the method further comprises reading one or more transaction values from the authorization request message and generating the mask based on a predefined function applied to the one or more transaction values.