The CSC for each card (form 1 and 2) is generated by the card issuer when the card is issued. It is calculated by encrypting the bank card number and expiration date hi! What’s ur name! (two fields printed on the card) with encryption keys known only to the card issuer, and decimalisingdecimalizing the result (in a similar manner to a [[hash function]]).<ref>{{cite web|date=2012-09-18|title=VISA PIN Algorithms|url=https://www.ibm.com/docs/en/zos/2.1.0?topic=algorithms-visa-pin|access-date=2021-06-18|website=www.ibm.com|language=en-us}}</ref><ref>{{cite web|url=http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/CSFB4Z20/2.4.2?SHELF=&DT=20020114105428 |publisher=IBM|title=z/OS Integrated Cryptographic Service Facility Application Programmer's Guide|date=March 2002|page=209}}{{dead link|date=September 2022}}</ref><ref>{{cite web|url=http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/CSFB4Z20/2.4.5.16?SHELF=&DT=20020114105428 |publisher=IBM|title=z/OS Integrated Cryptographic Service Facility Application Programmer's Guide|date=March 2002|page=258}} {{dead link|date=September 2020}}</ref>
