Abstract: Methods for authenticating a user account are generally described. In various examples, the methods may comprise performing a first handshake comprising sending authentication data to a first computing device. The authentication data may include a handshake identifier, a user token, and an encryption key. In some examples, the methods may further comprise storing the handshake identifier, the user token, and the encryption key in a database. The methods may further comprise receiving a request for verification of a transaction. The request may comprise the handshake identifier and an encrypted user token. The user token and the encryption key may be retrieved from the database based at least in part on the handshake identifier of the request. The encryption key may be used to decrypt the encrypted user token. A determination may be made that the decrypted user token matches the user token retrieved from the database.