Tidsstämpelbevis

Tidsstämpelbevis, or timestamping, is a service that cryptographically binds a document or data to a specific point in time. This is achieved by using a trusted third party, often called a timestamping authority (TSA), to digitally sign a hash of the document along with the current time. The TSA's signature ensures that the document existed in its current form at that specific moment and that it has not been altered since.

The process typically involves creating a hash (a unique digital fingerprint) of the document. This hash is then sent to the TSA, which combines it with the current date and time and signs this package with its own private key. The TSA then returns this signed timestamp to the user, who can store it alongside the original document. Anyone can later verify the timestamp by using the TSA's public key to confirm its signature and comparing the document's current hash with the one stored in the timestamp. If they match and the signature is valid, it proves that the document existed at the time indicated by the timestamp.

Timestamping is crucial for establishing the integrity and authenticity of digital records. It is used in various applications, including legal documents, intellectual property protection, software distribution, and audit trails, to provide irrefutable evidence of when a particular piece of information was created or existed. Without a timestamp, it can be difficult to prove the chronological order of events or the exact time of creation of digital assets, which is often a critical requirement for legal and business purposes. The trust in a timestamping service relies heavily on the security and reputation of the TSA.