摘要 |
There is provided a method of an electronic device for providing a one-time proof of knowledge about a one-time signing key to a server without revealing the one- time signing key. The method comprises computing a hash as a hash function from the one-time signing key, and transmitting, to the server, the computed hash, an identity associated with the electronic device and a hash path of the hash. There is also provided a method of a server of a signing authority for issuing a time stamp signature. The method comprises receiving a message from an electronic device, the message including a hash, an identity associated with the electronic device and a hash path of the hash, checking whether the hash corresponds to a one-time signing key for a root hash included in a public certificate associated with the identity, checking whether an index corresponding to the hash path from the one-time signing key to the root hash corresponds to a correct time slot, and determining it to be proven that the electronic device is in possession of the correct one-time signing key when the checks are fulfilled. Electronic devices, servers, and computer programs are also disclosed. |