Efficient methods for protecting identity in authenticated transmissions

A computer-implemented method comprising:

• receiving, by an access device, a message including a blinded user device public key and encrypted user device data from a user device, wherein the blinded user device public key is generated by the user device obfuscating a user device public key using a cryptographic nonce, the cryptographic nonce being a randomly generated value or a pseudo-randomly generated value, and wherein user device data is encrypted by the user device using a shared secret to obtain the encrypted user device data, the shared secret being different from the cryptographic nonce;
• generating, by the access device, the shared secret using an access device private key and the blinded user device public key, the access device private key associated with an access device public key;
• and
• decrypting, by the access device, the encrypted user device data using the shared secret.

A computer-implemented method comprising:

• generating, by a user device, a cryptographic nonce, the cryptographic nonce being a randomly generated value or a pseudo-randomly generated value;
• generating, by the user device, a blinded user device public key by obfuscating a user device public key using the cryptographic nonce, the user device public key associated with a user device private key;
• generating, by the user device, a shared secret using an access device public key of an access device, the user device private key, and the cryptographic nonce, the shared secret being different from the cryptographic nonce;
• encrypting, by the user device, user device data using the shared secret to obtain encrypted user device data;
• and
• sending, by the user device, a message including the blinded user device public key and the encrypted user device data to the access device, thereby allowing the access device to generate the shared secret using the blinded user device public key and an access device private key corresponding to the access device public key and to decrypt the encrypted user device data using the shared secret.