Legal Depot is a timestamp that proves you are in possession of a document at a given time
Trusted timestamping is the process of securely keeping track of the creation and modification times of a document. Security here means that no one - not even the owner of the document - should be able to change it once it has been recorded provided that the timestamper's integrity is never compromised. The legal deposit is a legal procedure where you can submit your work in order to timestamp it. In case of a dispute, this timestamp acts as a legal document for the authorities.