Computer-implemented methods and systems reliant on establishing a common session key between an electronic device and a computer server are disclosed. The method and systems may be for processing de-tokenization requests in payment transaction processing and for preparing an electronic device to perform payment transactions. During such a transaction, the server may perform a method that includes receiving a de-tokenization request including a payment token and a cryptogram generated by the electronic device using a session key generated by the electronic device based on a fingerprint of the electronic device, a secret value previously shared with the electronic device, the payment token, and a transaction counter; retrieving the fingerprint, the secret value, and the transaction counter and generating the session key based on the same; verifying the cryptogram using the session key; retrieving an associated account number; and sending response to the request including the account number.