DPX file

The DIGIPASS export file (DPX) is the file where all authenticator application data from a batch of Digipass authenticators are stored. In this file, the authenticator application data are encrypted with a key named software Digipass transport key. This key is a 128-bit 3DES key or a 256-bit AES key in charge of encrypting the sensitive data of the authenticator applications, such as the secret or sensitive settings used for the input of the cryptographic engine. The common parameters such as the codeword or the length of different application input are in clear text.

Software DPX file encryption

In case of standard DPX file encryption, the DPX file is generated by OneSpan and encrypted with a software-level DPX transport key only.

Figure: Flow of keys and DPX file with software DPX file encryption illustrates the flow of keys and the DPX file between the customer and OneSpan:

1. OneSpan generates the software-level DPX transport key, generates and encrypts the DPX file, and sends the DPX file to the customer.
2. OneSpan sends the software-level DPX transport key to the customer.

Figure:  Flow of keys and DPX file with software DPX file encryption