A method for sharing user information between a first device (Y) and a second device (Y) via a plurality of devices (Y -Y) 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) 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); 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) 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) 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); 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) 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); 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) 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) 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); and the second device (Y) decrypting the second coded data with the second private key (S 3) to get the user information.