Blockchain-based escrowed marketplace

One or more non-transitory computer-readable media storing instructions that, when executed by one or more processors, cause a system to perform operations, the operations comprising:

• obtaining, from a first entity, a predicate, a first purchase price, and a first public key associated with the first entity, the predicate used by the first entity to identity a token without revealing contents of the token;
• publishing the predicate, the first purchase price, and the first public key;
• obtaining, from a second entity, an encryption of the token and one or more knowledge-proving credentials of the token, the token satisfying the predicate, and the encryption of the token encrypted using the first public key;
• verifying ownership of the token based on the knowledge-proving credentials without access to the contents of the token;
• obtaining, from the first entity, an asset corresponding to the first purchase price;
• sending at least a portion of the knowledge-proving credentials to a token blockchain, the portion of the knowledge-proving credentials including an updated hash value, the updated hash value representing ownership of the token being transferred from the second entity to the first entity;
• verifying that the updated hash value is posted to the token blockchain;
• providing the encryption of the token to the first entity;
• and
• transferring the asset corresponding to the first purchase price to the second entity.