Patent attributes
Provided is a method according to the present invention comprising the steps of: (a) generating a message digest of a particular file when a request for authenticating same is obtained; (b) when a message digest encoded with a private key of a first user and a message digest encoded with a private key of a second user are obtained, and if the (i) (A) information for the message digest, which was encoded with the private key of the first user, decoded with a public key of the first user, (ii) (B) information for the message digest, which was encoded with the private key of the second user, decoded with a public key of the second user, and (C) the message digest generated in step (a) match, then registering, in a database, a hash value of the message digest encoded using the private key of the first user, private key of the second user and a private key of a server; and (c) obtaining a transaction ID reflecting location information of the registered hash value in the database.
