Aikaleimajärjestelmät

Aikaleimajärjestelmät, often translated as timestamping systems, are technologies that assign a unique and verifiable timestamp to digital data, such as a document, transaction, or message. This timestamp proves that the data existed at a specific point in time and has not been altered since. The primary goal of these systems is to ensure data integrity and authenticity.

The process typically involves creating a cryptographic hash of the data. This hash is a unique digital fingerprint. The timestamping authority (TSA) then combines this hash with a precise time and signs it with its own private key. This signed bundle is often referred to as a timestamp token. Anyone can verify the token by checking the TSA's signature and by comparing the hash within the token to a new hash generated from the original data. If they match, and the timestamp is valid, it confirms the data's existence at that time.

Aikaleimajärjestelmät are crucial in various applications. They are used in digital signatures to provide proof of when a document was signed, in legal contexts to validate evidence, in financial transactions to record the exact time of trades, and in secure communication protocols. The reliability of a timestamping system depends heavily on the trustworthiness and security of the TSA.