The present invention relates to a method for issuance of a personalized user device, wherein the method comprises initializing a user device to provide an initialized user device, providing device initialization data to an issuer system, wherein the device initialization data comprises a public device key and a public issuer authentication key, calculating a user private key, encrypting the user private key and the public device authentication key with the public device key to provide encrypted data, digitally signing the encrypted data using a private issuer key to provide signed encrypted data, the issuer system providing the encrypted data and the signed encrypted data, injecting said data into the initialized user device to provide the personalized user device, and the personalized user device, conditional on successfully validating the signed encrypted data, decrypting the encrypted data to retrieve the user private key and the public device authentication key.