Open source cryptographic extensions to OpenRTB protocol proposed by the AdLedger consortium to improve the integrity of the digital advertising ecosystem by creating an immutable identity for supply chain participants, a verifiable chain of custody, and sophisticated tools for data access and validation.
CryptoRTB achieves these goals by inserting an encrypted object into the OpenRTB bid request that contains two sections: the digital signature and a set of claims. A digital signature is a cryptographic technique used to prove the authenticity of a message and the identity of its originator. CryptoRTB protocol proposes a digital signature comprised of a public key and a private key. The public key is shared in OpenRTB messages, and is stored on a public blockchain so that anyone may validate the public identity of a given party. The private key is necessary for a party to create their digital signature, but is never shared in order to maintain security. The claims section can include anything the originator of the message would like to certify as true, such as meta data like domain name, player size, buyer seat, advertiser domain, etc., or first party user data.