Abstract: A computing system receives a request from a client device to verify a document associated with a user of the client device. The request includes an identity token of the user and the document to be verified. The computing system generates a hash value corresponding to the document using a public key. The computing system identifies a plurality of previously generated hash values linked to the identity token. Each of the plurality of previously generated hash values were generated using the public key by a second computing system distinct from the computing system. The computing system compares the generated hash value to the plurality of previously generated hash values. The computing system determines that the generated hash value matches at least one of the previously generated hash values. Based on the determining, the computing system confirms that the document is authentic.