A .tsd or .m7m file is not a 3D scene: in Italy it is a document, often already signed as a .p7m, packed with its timestamp (marca temporale), a trusted date issued by a time-stamping authority. Open it here in your browser, get the document out and see, for each timestamp, the time, the authority and whether the imprint still matches the data. The file is not uploaded.
Updated on · by Maurizio Fonte
The file stays on your device: opening, extraction and checks run in the browser. The only network request is the part of the EU trusted lists about the timestamp authority.
Drop the .tsd or .m7m on the box, or tap it to pick the file from your phone or computer. The file is not sent to a server.
Each timestamp shows its trusted time, the authority that issued it, whether its imprint matches the data and whether the authority was qualified at that time.
Download the stamped document, or open it in a new tab if it is a PDF or an image. If it is a signed .p7m, the viewer opens it and shows who signed it.
Copy report gives you a plain text with time, authority and the result of each check, ready to attach to a file or forward.
A timestamp is a small document signed by a time-stamping authority that says: this data existed at this moment. It does not hold the data, it holds its imprint, a value computed from the data with a hash function (usually SHA-256). Change one byte of the document and the imprint no longer matches.
The viewer runs three checks on each timestamp. It recomputes the imprint over the data the timestamp travels with and compares it with the one the authority recorded. It verifies the timestamp's signature with the authority certificate carried in the file. It looks the authority up in the EU trusted lists to see whether, on that date, it was a qualified time-stamping service.
In a .tsd the first timestamp covers the content (and the metadata, when the file says they are protected). Later timestamps are renewals: each one covers the previous timestamp, so the trusted date outlives the expiry of the authority certificate. The viewer checks the whole chain and tells you which link fails, if one does.
An .m7m holds a single timestamp, computed over the .p7m file packed with it. If the timestamp of another document was paired with it by mistake, the imprint does not match and the viewer says so.
The document inside is extracted as it is. If it is a .p7m, a digitally signed document, the viewer opens it and shows who signed it.
Under the EU eIDAS Regulation (Regulation (EU) No 910/2014, Article 41) a qualified electronic time stamp enjoys the presumption of the accuracy of the date and time it indicates and of the integrity of the data it is bound to. That is why the check looks at whether the authority was qualified on the date of the timestamp, not today.
This viewer helps you read the file and see whether the technical checks hold, but it is not a verifier connected to revocation lists: revoked or suspended authority and signer certificates are outside what it can see. For use in court or in a tender, use the verifier of the provider that issued the timestamp or one listed by AgID, the Italian digital agency.
A .tsd follows the international standard RFC 5544 (TimeStampedData): one file holding the document and one or more timestamps, with optional metadata such as the file name. It is the most portable format and supports renewals.
An .m7m is a container that came from the signing software common in Italy: a MIME file with two attachments, the signed .p7m document and the timestamp as a .tsr. Not every program reads it, which is why people search for how to open one.
A .tsr (or .tst) is the timestamp alone, per RFC 3161, without the document: to verify it you also need the file it refers to. Note that the .tsd extension is also used by some 3D modelling software for scene files, which have nothing to do with timestamps.
Technical terms used on this page, briefly explained.
Laws, official tables and reference implementations the logic of this tool was checked against.
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