Abstract: A method, system, and computer program product is provided for third-party authorization. The method includes generating an authorization code, encrypting the authorization code with a public key associated with a first system, resulting in an encrypted authorization code, transmitting the encrypted authorization code to the first system, receiving, from the first system, a digitally signed authorization code generated by the first system based on the authorization code and a private key corresponding to the public key associated with the first system, verifying the digitally signed authorization code based on the public key and the authorization code, and in response to verifying the digitally signed authorization code, transmitting an access token to the first system, wherein the access token is configured to authorize a user with the first system.