What is a trusted timestamp? This article explains its principles, functions, and practical applications.

　　In scenarios such as website operation, software development, electronic contracts, and copyright protection, you may frequently encounter the term "trusted timestamp." Many people are puzzled upon first hearing this: Isn't a timestamp just a display of time? Why does it need to be "trusted"? Isn't the time on a computer reliable? Why do websites, files, and code need trusted timestamps? In fact, a trusted timestamp is not simply a "time display," but an important mechanism with evidentiary value both legally and technically.

　　Let's first explain what a trusted timestamp is in one sentence:

　　A trusted timestamp refers to a time certificate generated by a trusted third-party organization that proves that certain data existed before a specific time and has not been tampered with since.

　　The key words are only three: third-party, immutable, and verifiable. This is the true meaning of "trusted."

　　Why are ordinary timestamps "untrustworthy"?

　　Before understanding trusted timestamps, let's look at the problems with ordinary timestamps.

　　Where do ordinary timestamps come from? For example, file creation time, website publication time, and database record time all essentially come from computer system time and server time.

　　System time can be easily changed. For example, if you change your computer's time to 2020 and create a new document, the document's time will also show as 2020. What does this mean? Ordinary timestamps cannot prove "that it actually existed at that time," nor can they prove whether it was modified afterward. In legal, copyright, and evidentiary scenarios, they have almost no probative value.

　　The Core Problems Trusted Timestamps Solve

　　Trusted timestamps primarily solve three key problems: when did the data exist? Has the data been modified since then? And can this time be recognized by a third party? Ordinary timestamps cannot address any of these three points.

　　How do trusted timestamps work? (Simplified Version) Many people find the principles daunting, but it can be understood with a relatable analogy. Think of it like "stamping a time stamp" on a document. Imagine you wrote an important document, took it to a notary office, and the notary office stamped the document, noting the date. Later, if anyone questions, "Did you write this later?" you can say, "Impossible, the notary office already stamped it at this time." A trusted timestamp is essentially a "digital notary stamp." What happens technically? The simplified process is: hash the file content, submit the hash value to a trusted timestamp service provider, and the provider generates a timestamp using its private key and the current standard time, returning an unforgeable time certificate. The key is that the time comes from an authoritative time source, the signature cannot be forged, and even changing a single word in the file will cause verification to fail.

　　Why is a "third party" essential? This is the soul of a trusted timestamp. Self-stamping lacks persuasiveness. If your own server generates the timestamp: you can change the time, you can change the data, proving you have the final say. In legal or dispute situations, this is practically equivalent to having no evidence. A third party signifies "independence and impartiality." Trusted timestamp services are typically provided by authoritative institutions, compliant platforms, and legally recognized service providers. They have no vested interest in the data itself, making them more reliable.

　　What are the practical uses of trusted timestamps?

　　1. Website content copyright protection (essential reading for webmasters). For website owners, trusted timestamps are extremely useful. They prove article publication dates, preserve original content, prevent plagiarism accusations, and in case of disputes, prove that "this content existed in a certain month and year."

　　2. Software, code, and algorithm ownership verification. Developers often use trusted timestamps to prove the completion time of code snippets and the formation time of technical solutions, which is crucial in intellectual property disputes.

　　3. Electronic contracts and electronic evidence. Trusted timestamps are commonly used for electronic contract signing dates, data submission dates, and operation log preservation. This is why many electronic contract platforms integrate timestamp services.

　　4. Corporate compliance and auditing. Enterprises can use trusted timestamps to solidify business data, prevent subsequent tampering, and improve compliance credibility.

　　Is a trusted timestamp always "legally valid"?

　　This is a question many people are concerned about. The conclusion is: its validity depends on the compliance of the service provider and the usage scenario.

　　Generally speaking, reliable timestamps provided by compliant organizations have a high acceptance rate in judicial, arbitration, and evidence collection processes, but they are not "all-purpose evidence" and still need to be combined with other materials.

　　In summary: Remember reliable timestamps in one sentence: a reliable timestamp does not "display time," but rather "proves time." It doesn't solve the problem of "what time it was," but rather whether someone can prove that the data existed before that specific time.