Problem
You need to decrypt transaction data. And all you've got, besides the data, is a KSN (and a test key).
Solution
Grab the ID TECH Encrypt/Decrypt Tool. Select "Encrypt or decrypt data" option, then use the Derive button to enter your KSN and derive a session key. In the main window, enter your encrypted data in the Data pane, put the derived (session) key in the Key pane, and click Decrypt. If need be, use the AES checkbox at the bottom of the page. Otherwise, TDES is the default decryption algorithm.
Related articles