Transmitting sensitive information securely over unsecured networks without authentication

Methods and apparatus for encrypting and decrypting data for wearable devices that are not based on authentication techniques, such as login/password or handshaking, are provided. A computing device receives a message. The message includes encrypted data and a cryptographic reference. The encrypted data includes physiological data of a wearer of the wearable device. The cryptographic reference includes a reference to a first cryptographic technique. The computing device determines the first cryptographic technique based on the reference to the first cryptographic technique. The computing device determines a cryptographic key. The computing device decrypts the encrypted data using the first cryptographic technique and the cryptographic key to obtain decrypted data. The computing device stores the decrypted data.