Smart contracts without a blockchain? Trusted timestamping is the process of securely keeping track of the creation and modification time of a document. Security here means that no one - not even the owner of the document - is able to change it once it has been recorded.
There are two common methods to get a secure timestamp. 1) creation of a digital timestamp certificate from a trusted timestamp autority. 2) incorporate a hash into a transaction stored in the blockchain.
We prefer the first method, mainly because of speed and reliablity. We use the free services of freeTSA.org, and you get your certificate within 1 second in your mailbox!