A method for sharing user information between a first device (Y ) and a second device (Y ) via a plurality of devices (Y -Y(N)) with memory connected to a network using distributed ledger technology, the first device (Y ) having the user information and the second device (Y ) not having the user information, comprising: the first device (Y ) connected to the network outputting coded data associated with the user information to the network , wherein the coded data is encrypted with a first public key (P 1 ) corresponding to a first private key (S 1 ) for the user information, wherein the first private key (S 2 ) is stored or managed in the first device (Y ) ; each device of the plurality of devices (Y -Y(N)) receiving the coded data through the network to store in the memory of the each device, so that the same coded data is stored among the plurality of devices (Y -Y(N)); the second device (Y ) connected to the network outputting a request for acquiring data from the network , wherein the request is provided toward the plurality of devices (Y -Y(N)) and comprises a second public key (P 3 ) corresponding to a second private key (S 3 ) for the user information, and wherein the second private key (S 3 ) is stored or managed in the second device (Y ); in response to the request for acquiring data, the first device (Y ) decrypting the coded data with the first private key (S 1 ) and subsequently outputting a second coded data associated with the user information to the network , wherein the second coded data is encrypted with the second public key (P 3 ) included in the request for acquiring data; each device of the plurality of devices (Y -Y(N)) storing the second coded data in its own memory, so that the same second coded data is stored among the plurality of devices (Y -Y(N)); and the second device (Y ) decrypting the second coded data with the second private key (S 3 ) to get the user information. the first device (Y ) connected to the network outputting coded data associated with the user information to the network , wherein the coded data is encrypted with a first public key (P 1 ) corresponding to a first private key (S 1 ) for the user information, wherein the first private key (S 2 ) is stored or managed in the first device (Y ) ; each device of the plurality of devices (Y -Y(N)) receiving the coded data through the network to store in the memory of the each device, so that the same coded data is stored among the plurality of devices (Y -Y(N)); the second device (Y ) connected to the network outputting a request for acquiring data from the network , wherein the request is provided toward the plurality of devices (Y -Y(N)) and comprises a second public key (P 3 ) corresponding to a second private key (S 3 ) for the user information, and wherein the second private key (S 3 ) is stored or managed in the second device (Y ); in response to the request for acquiring data, the first device (Y ) decrypting the coded data with the first private key (S 1 ) and subsequently outputting a second coded data associated with the user information to the network , wherein the second coded data is encrypted with the second public key (P 3 ) included in the request for acquiring data; each device of the plurality of devices (Y -Y(N)) storing the second coded data in its own memory, so that the same second coded data is stored among the plurality of devices (Y -Y(N)); and the second device (Y ) decrypting the second coded data with the second private key (S 3 ) to get the user information. <EOS>