| 摘要 |
A device includes a backup activator and a backup generator. The backup activator decrypts an encrypted concealed snapshot of a user's secret using a protection key, producing a concealed snapshot, and reconstructs a snapshot from the concealed snapshot, the user's password and a multiparty secret reconstruction system. The backup generator conceals the snapshot with a password of the user and the multiparty secret protection system, generates the protection key and encrypts the concealed snapshot with the protection key. The backup activator includes a helper based key recovery unit which sends encrypted portions of the protection key, each portion being associated with and decryptable by a helper, and which combines decrypted portions into the protection key. The backup generator includes a helper based key encrypter to split the protection key into at least one portion per an associated helper and to encrypt each portion with the associated helper's public key. |
