System, method, and computer program product for third-party authorization

A system comprising an authorization system including at least one processor programmed or configured to:

• receive a request through a first website associated with a first system, the request initiated by a user through a computing device;
• present, on the computing device of the user, an access grant page;
• receive, from a second system separate from the first system and the first website, access grant data comprising a user identifier associated with the user and at least one grant selected from the access grant page;
• generate an authorization code based on receiving the access grant data;
• after generating the authorization code, encrypt the authorization code with a public key, resulting in an encrypted authorization code;
• transmit the encrypted authorization code to the first system;
• in response to transmitting the encrypted authorization code to the first system, receive, 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;
• after receiving the digitally signed authorization code from the first system, verify the digitally signed authorization code based on the public key and the authorization code;
• and
• in response to verifying the digitally signed authorization code, transmit a token to the first system, wherein the token is configured to authorize the user with the first system.

A computer program product comprising at least one non-transitory computer-readable medium including program instructions that, when executed by at least one processor of an authorization system, cause the at least one processor to:

• receive a request through a first website associated with a first system, the request initiated by a user through a computing device;
• present, on the computing device of the user, an access grant page;
• receive, from a second system separate from the first system and the first website, access grant data comprising a user identifier associated with the user and at least one grant selected from the access grant page;
• generate an authorization code based on receiving the access grant data;
• after generating the authorization code, encrypt the authorization code with a public key, resulting in an encrypted authorization code;
• transmit the encrypted authorization code to the first system;
• in response to transmitting the encrypted authorization code to the first system, receive, 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;
• after receiving the digitally signed authorization code from the first system, verify the digitally signed authorization code based on the public key and the authorization code;
• and
• in response to verifying the digitally signed authorization code, transmit a token to the first system, wherein the token is configured to authorize the user with the first system.