A timestamp is an electronic data that determines the time when an electronic data was produced, modified, sent, received, recorded. Timestamps prove that a data exists on the specified date. The timestamp server uses public key technology to sign timestamps, confirming the integrity of data and its existence at a particular date.

According to Electronic Signature Law No. 5070, Time Stamp refers to the record verified by electronic signature by the electronic certificate service provider in order to determine when an electronic data was produced, modified, sent, received or recorded. Timestamps are often used for digital logging or event sequences. In this case, each event in the log or event thread is marked with a timestamp. In file systems, a timestamp records the date a file was created or modified.

Valid Timestamp service in Turkey is provided by Electronic Certificate Service Providers (CSP).

ISO 8610 standardizes the representation of date and time. These standards are often used to generate timestamp values.

Purpose of Time Stamps

There is a need for a timestamp in web applications where money is transferred, an application is made, a photograph, an idea, a research, a formula, etc. The main purpose of the timestamp is to verify the data, but besides this, it has started to be used and widespread in many areas in the internet world. Timestamps are needed to prove the accuracy, integrity and existence of data by those who own digital assets. Timestamps are frequently used to make more efficient forensic studies and evidence that may be uncovered, especially after a cyber attack. The timestamp is also used to control the risks that arise due to the intense use of the internet in all areas of human life, namely cybercrime and attacks. It is especially needed in institutions or organizations where internet use is provided in a common network.

Areas Where Time Stamp is Used

⦁ Documents signed with e-signature
⦁ Archive signed documents
⦁ E-invoices
⦁ E-books
⦁ Sent emails
⦁ Incoming-Outgoing documents
⦁ Musicians' works
⦁ Authors' writings
⦁ Website owner sites
⦁ Designs
⦁ Programs

Creating a Timestamp

The algorithm of the timestamp is based on the hash function logic.

⦁ Hash information of the file is extracted. (SHA256, SHA512, ECC384 etc.)
⦁ The generated hash information is sent to the Timestamp Server (TSA).
⦁ TSA combines the hash information with the time information and the hash value of the new information is obtained.
⦁ The new hash is signed with the TSA secret key, using the digital signature method.
⦁ The signed hash information creates the stamp information and the timestamp is sent back to the user as the stamp, so that the data whose hash value is calculated can be proven to exist before the timestamp date.
⦁ Incoming stamp information is stored with the relevant one.