Requirements for SHASIGN:sup
All parameter names should be in UPPERCASE (to avoid any case confusion)
All parameters have to be arranged alphabetically
Parameters that do not have a value should NOT be included in the string to hash
A string hashed with the SHA-1 algorithm will always be 40 characters long
Merchant supports identification but not cardholder, The merchant has a 3-D Secure contract, but the cardholder's card is not 3-D Secure or is 3-D Secure but the cardholder is not yet in possession of the PIN (Half thumbs up).