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7

I would characterize the service as similar to a trusted time-stamping service. Except they do not do the time-stamping, but just provide the "key". This allows a user to decide what do to with it, such as using it as a private key to sign something, or an HMAC key, proving the signature is "not older" than the timestamp. If the signature is published to a ...


7

If you search on "timestamp", "timestamping", and "notary" on Crypto.SE and Security.SE, you'll find lots of references. I've collected a number of timestamping services that were mentioned in one of those places; this should provide a number of companies and online services you can check out: http://www.proofofexistence.com/ https://www.btproof.com/ ...


3

I wonder why anyone would choose to rely on a source of true random numbers fraught with questions that will ultimately have no provable - or perhaps even satisfactory - answer. There are at least a couple of companies that sell generators that provide high quality true random numbers. Having a generator on-site and available real-time allows the necessary ...


3

Several certificate authorities operate RFC-3161-compliant time-stamp servers that can be used free-of-charge. OpenSSL can create RFC 3161 time-stamp requests and verify the responses. Here is a simple Bash script that time-stamps a file using the time-stamp server operated by StartSSL: in_file='[path to file]' # name of file to be hashed and time-stamped ...


3

You can prove that a document was signed after a certain date by including data that was not known to anyone before that date, such as stock market data. You cannot prove that a document was signed before a certain date by purely cryptographic means. Information doesn't go stale, so when you show a signature, it could have been signed at any time. You can ...


1

I think that you're asking how to generate a timestamp response as defined in timestamp-protocol: RFC3161, with openssl to generate and sign the response using a PKCS#11 (HSM in your case) as a TSA signer. I think that there is no native way to use PKCS#11with openssl to do this. (maybe with some plugin like: opensc pkcs11 engine for openssl). If you take ...


1

Your diagram is not very clear, but XOR is not a good combiner function to use for timestamping, as it may allow backdating in some circumstances. For instance, see the "time travel" attacks in Section 3.3 of the following paper (e.g., pp.179-180): Cryptanalytic Attacks on Pseudorandom Number Generators. Depending upon how many inputs you have to the XOR ...


1

First up: Don't believe the hype! Especially if things can easily be proven wrong. What I mean is that your NIST have just launched a new serviceā€¦ is incorrect, as the NIST Randomness Beacon project is known to me (and others) since 2011. Furthermore, this project was awarded a multi-year grant from NIST's Innovations in Measurement Science (IMS) Program in ...



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