Abstract: A method is implemented in a networked computer system that is connected to document issuers and validators and interacts with a blockchain. It comprises generating a master key assigned to an issuer, certifying a document through a first process including generating a document persistence key, encrypting document data with an encryption algorithm and an encryption key derived from three keys (the master key, the document persistence key and an intermediate key), registering encrypted document data in the blockchain, and generating a web address carrying recovery information of the certified document; reading the document through a second process accessible to the web address, the second process including recovering the encrypted data in the blockchain and accessing the three keys, decrypting the encrypted data using the encryption key derived from the three keys, and displaying the document; and upon request from a legitimate holder of the document erasing the persistence key.

Abstract: A method is implemented in a networked computer system that is connected to document issuers and validators and interacts with a blockchain. It comprises generating a master key assigned to an issuer, certifying a document through a first process including generating a document persistence key, encrypting document data with an encryption algorithm and an encryption key derived from three keys (the master key, the document persistence key and an intermediate key), registering encrypted document data in the blockchain, and generating a web address carrying recovery information of the certified document; reading the document through a second process accessible to the web address, the second process including recovering the encrypted data in the blockchain and accessing the three keys, decrypting the encrypted data using the encryption key derived from the three keys, and displaying the document; and upon request from a legitimate holder of the document erasing the persistence key.