Generally, a timestamp is the current time of an event that is recorded by a computer. You can use digital timestamps via a trusted authority to certify and protect your intellectual property or your records integrity.

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Does OpenTSA support PKCS11 to talk to HSMs?

We are planning to implement the time-stamping service (RFC 3161) using OpenTSA wanted to know: Does OpenTSA support PKCS-11 (Cryptoki) to talk to HSMs? BTW: I did not find documentation or much ...
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How can I know when a file was signed?

I have been thinking about digitally signed documents (Word files and PDF files) and can not get over the fact about - how can I securely know when the file was signed? Scenario: If the date of the ...
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91 views

Timestamping using a hashed linked list and public known events

Let's say we have a timestamping scheme of the following characteristics, The hashes of the documents we are trying to timestamp are XOR'ed with "events" whose time of occurrence are very publicly ...
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Is timestamping possible without publishing?

The Wikipedia article Trusted Timestamping states that we can timestamp data by publishing it's hash. Publishing can be done either independently or via a third-party publisher, as explained by ...
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How useful is NIST's Randomness Beacon for cryptographic use?

NIST have just launched a new service called the NSANIST Randomness Beacon. It has been met with some initial skepticism. Perhaps the cryptography community would have used it before June 2013 when ...
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A timestamping authority (digital notary)

Does there currently exist a free online service that accepts a file, hashes it, takes an authoritatively chosen timestamp (from one or more time services), signs these and sends this signed message ...
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Why use a timestamp and how can someone know it's the correct one?

Let's say A wants to send a message, so everyone who gets the message, can be assured that it's from A. A then sends a message ...
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Is there an algorithm or hardware that can sign/verify natural time?

PGP/GPG can used to sign text, others use public key to verify them. So one could say, that these cryptographic algorithms deal with space. Are there any algorithms that can deal with time? E.g. I ...
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Is it possible to cryptographically prove when was the last time a ciphertext was decrypted/encrypted?

I want to provide a service that encrypts and decrypts documents and I want to provide the users with proof that I haven't stolen their secret key and read their documents. I know I can prove when a ...
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Signature and Timestamp for Long Term Document Archival Question

I have a PDF document intended for long-term (many years, maybe decades) archival which I would like to digitally sign with my personal certificate to ensure its integrity. As far as I understand, I ...
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How are timestamps verified?

You put an input and the hash value comes as an output then when someone puts the input the hash function it is applied to see if it is the same hash original value is stored in some database , that ...
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Timestamping services authorities, utilizing Linked, hybrid and other than PKI schemes

What are well respected Cryptographic Timestamping authorities utilizing more sophisticated than just PKI (RFC 3161) schemes, like Linked, Linked and signed, distributed hash trees (maybe P2P?), ...