Techniques for interoperable cryptographic peer and server identities can include receiving a message, in a connection establishment transaction, from an endpoint, the message including an endpoint discriminator, selecting a certificate based on the endpoint discriminator, determining a cryptographic scheme based on the selected certificate, and establishing the requested connection with the endpoint using the determined cryptographic scheme. The techniques can also include accessing one or more hashes, each hash being a hash of at least a portion of a certificate, processing the endpoint discriminator for an identity object, and comparing the identity object with the one or more hashes to identify a matching hash. The selected certificate can correspond to the matching hash. These techniques can allow an endpoint to interoperate with other endpoints that use different or similar cryptographic schemes.