A method for securely sharing validation information of one or more data files stored on different cloud servers using distributed ledger technology, the method comprising: a) requesting access to the data files of a user stored on the cloud servers , wherein the data files are requested by a company registered to a main blockchain to secure a Know Your Customer, KYC, process in response to a request from the user to enter into a contract with the company ; b) calculating, by the company , a hash of the data files; c) constructing, by the company , a structured Merkle tree using the hash of the data files and additional hashes received from the user , the additional hashes being hashes of other data files for which the user has not granted access, but has used to construct a corresponding Merkle tree for which the user has committed a root value to the main blockchain to which the user has registered; d) checking, by the company , whether the root value of the Merkle tree constructed in step c) is the same as the one the user has committed to the main blockchain ; e) checking, by the company , whether the hash of the data files is stored in a block of a satellite blockchain linked to the main blockchain and operated by a subset of nodes of the main blockchain that trust one another; f) based on a determination in step e) that the hash of the data files is already stored in the satellite blockchain , validating, by the company , the data files without undergoing any other validation process, and based on a determination in step e) that the hash of the data files is not already stored in the satellite blockchain or in a different satellite chain linked to the main blockchain , performing a separate validation process, and then issuing, by the company , a transaction in a new block on the satellite blockchain including the hash of the data files; and g) issuing, by the company , the contract once the data files have been validated. a) requesting access to the data files of a user stored on the cloud servers , wherein the data files are requested by a company registered to a main blockchain to secure a Know Your Customer, KYC, process in response to a request from the user to enter into a contract with the company ; b) calculating, by the company , a hash of the data files; c) constructing, by the company , a structured Merkle tree using the hash of the data files and additional hashes received from the user , the additional hashes being hashes of other data files for which the user has not granted access, but has used to construct a corresponding Merkle tree for which the user has committed a root value to the main blockchain to which the user has registered; d) checking, by the company , whether the root value of the Merkle tree constructed in step c) is the same as the one the user has committed to the main blockchain ; e) checking, by the company , whether the hash of the data files is stored in a block of a satellite blockchain linked to the main blockchain and operated by a subset of nodes of the main blockchain that trust one another; f) based on a determination in step e) that the hash of the data files is already stored in the satellite blockchain , validating, by the company , the data files without undergoing any other validation process, and based on a determination in step e) that the hash of the data files is not already stored in the satellite blockchain or in a different satellite chain linked to the main blockchain , performing a separate validation process, and then issuing, by the company , a transaction in a new block on the satellite blockchain including the hash of the data files; and g) issuing, by the company , the contract once the data files have been validated. <EOS>