[TriLUG] OT: crytographic timestamps

[Justis Peters]

Joseph Mack NA3T wrote:
> I'm writing some proprietary code at home in stages and will 
> be submitting it remotely. It would be helpful if I could 
> conveniently show the date that I submitted each stage. One 
> way I can think to do this is to cryptographically timestamp 
> it. This in turn needs a trusted timestamp authority (TSA). 
> The only FOSS TSA project I could find with google appears 
> to have died (at least from timestamps on the postings). 
> There are plenty of people selling proprietary TSA hardware. 
> If it comes to that, I'll just do without.
>
> Alternately I could swipe some time sensitive material from 
> an on-line news source and cryptographically encapsulate 
> that in the code. This would give me a "no older than" date, 
> which is not terribly useful.
>
> I would like this to be as paperless as possible, as I may 
> need to keep records for a long time (10yrs). eg I don't 
> really want to go to the Post Office and collect pieces of 
> paper, saying when I mailed the code.
>
> Any ideas?
>   
Joe,

I've also had an interest in this topic and used your email as motive to 
finally do a few minutes of searching on the topic. Here's a Wikipedia 
article that's a decent starting place. If nothing else, it provides 
more keywords to use in searching for a provider:
  http://en.wikipedia.org/wiki/Trusted_timestamping

Here are two free services that I found from there:
  http://www.signedtimestamp.org/
  http://www.itconsult.co.uk/stamper.htm

Myself, I am considering paying a modest fee for the service, so they 
have a motive to stay in business. Here are the first couple leads I 
found for commercial providers. The first provider claims $0.40 per 
timestamp and signs on the fingerprint, not the whole file. This is an 
interesting tactic, because it does not require you to disclose your 
material to a third party and also scales well to very large data sets:
  http://www.e-timestamp.com/timestamp.htm
  http://www.echosign.com/

Best of luck in your pursuits.

Kind regards,
Justis Peters
http://justis.indythinker.com