In each message involving transmission of a PIN, the PIN value is encrypted using Triple DES algorithm in ECB mode with a shared encryption key agreed upon outside the API. The cipher text is encoded with Base64 (RFC1341) and passed as the PIN parameter.
3DES ECB algorithm operates on 8-byte blocks. The transmitted value will always be 12 characters long because of Base64 encoding of 8-byte cipher text. Use of 3DES makes a data unreadable without knowing the key. 3DES is derived from the well know DES algorithm except that in 3DES the data block is Encrypted, decrypted. and encrypted 3 times and hence the name 3DES.
Clients can encrypt the PINS with the key that they choose. Once the PIN is encrypted, clients need to transmit the key to Digital Payments in the Base64 encoded format. Make sure that your data is URL encoded) before it is transmitted. This is absolutely imperative, since “+”, “/”, “= are special character and have a special meaning in the URL. For safe transmission of these characters, the URL data needs be encoded before it is transmitted.