A method for mapping at least two authentication devices (101, 102, 103) to a user account using an authentication server (201, 202), wherein each authentication device (101, 102, 103) connects to the authentication server (201, 202) using a secured communication channel; and their mapping to the account of said user is recorded on the authentication server (201, 202); and during any transfer of data between the authentication devices (101, 102, 103) mapped to the account of said user, the data is transmitted from one authentication device (101, 102, 103) to the authentication server (201, 202) using a secured communication channel, and from the authentication server (201,202) to one other authentication device (101, 102, 103) mapped to the account of said user using a secured communication channel when the one other authentication device (101, 102, 103) creates the said secured communication channel, characterized in that simultaneously with the mapping of a second authentication device (101, 102, 103) to the user account on the authentication server (201, 202), the second device being any authentication device other than a first authentication device the first authentication device being any authentication device which has already been mapped to the user account, the first authentication device transmits an authentication device secret to the second authentication device (102, 103) directly, without the intermediary of the authentication server (201, 202), and the authentication device secret is stored on the second authentication device (102, 103); wherein if the mapping of the second authentication device (102, is the first mapping of another authentication device, the first authentication device generates the authentication device secret, and, at each following mapping of another authentication device, the authentication device secret stored on the first authentication device (101, 102) is transmitted; the authentication device secret is subsequently used in transferring of data containing sensitive information among authentication devices (101, 102, 103) mapped to the account of said user to encrypt at least the sensitive information; or simultaneously with the mapping of a second authentication device (101, 102, 103) to the single user account on the authentication server (201, 202), the second authentication device being any authentication device other than a first authentication device, the first authentication device being any authentication device which has already been mapped to the user account, the first authentication device transmits a one-time secret to the second authentication device (102, 103) directly, without using the authentication server (201, 202), and subsequently an authentication device secret is transmitted from the first authentication device to the authentication server (201,202) using a secured communication channel and from the authentication server (201, 202) to the second authentication device (102, 103), encrypted using the one-time secret, and after decryption by the one-time secret, the authentication device secret is stored on the second authentication device (102, 103), wherein, if the mapping of the second authentication device (102, 103) is the first mapping of another authentication device, the first authentication device generates the authentication device secret; and at each following mapping of another authentication device, the authentication device secret stored on the first authentication device (101, 102) is transmitted, and the authentication device secret is subsequently used in transferring of data containing sensitive information between authentication devices (101, 102, 103) mapped to the account of said user to encrypt at least the sensitive information.