| 摘要 |
There is provided a method of a server for deriving a time stamp for a piece of data. The method comprises receiving a signing request from a client comprising a hash value of the piece of data, wherein the hash value is formed using a time-forwarded one-time signing key, OTSK, wherein the time- forwarded OTSK comprises a time-forwarded index, queuing the signing request, pushing the hash value to a signature infrastructure entity at the time-forwarded time, and receiving a time stamp from the signature infrastructure entity. There is also provided a method of a client for signing a stream of pieces of data by obtaining a time stamp for each piece of data. The method comprises collecting the pieces of data and deriving one-time signing keys of a one-time signing key hash chain, forming a stream of signing requests for the pieces of data by applying the one-time signing keys with time- forwarded indices for the respective piece of data to calculate hash values of the respective pieces of data, and transmitting the stream of signing requests comprising the hash values to a server for deriving time stamps for the pieces of data, respectively. A server, an electronic device and computer programs are also disclosed. |
