[Cryptography] Best Internet crypto clock ?

Bear bear at sonic.net
Wed Oct 8 11:57:27 EDT 2014

On Fri, 2014-10-03 at 06:42 -0700, Henry Baker wrote:
> At 11:29 PM 10/2/2014, Ryan Carboni wrote:
> >"Each such value is sequence-numbered, time-stamped and signed, and includes the hash of the previous value to chain the sequence of values together and prevent even the source to retroactively change an output package without being detected."
> >They are both block chains.
> >
> >And they both include the time.
> So you can easily convert from cryptotime to GMT time.
> What is the authenticated algorithm to convert GMT time to cryptotime
> for a) Bitcoin blockchain; b) NIST whatever-its-called ?
> And unlike Bitcoin, where millions of processors are working very hard
> to make sure that it can't be hacked, where are those millions of
> processors to make sure that the NIST chain can't be hacked?

I have to point out here that there is absolutely nothing in the Bitcoin
protocol that prevents servers who solve a block from misreporting 
the time.

In fact, it has been a strategy in the past for parallelizing the
hashing. When the portion of the nonce that people could adjust 
seeking a winning hash was exceeded by hardware capacity, the 
time field was incremented even though the mentioned time had 
not yet arrived, and the search started over.  Because that was 
faster than rearranging the transactions to form a different 
base for hashing, I guess.  

Anyway, the time reported in bitcoin blocks is approximate, and 
historically not even monotonically increasing.  It is testimony
that the Bitcoin network accepted the server's claim of what 
time it was, so probably, usually, within ten minutes of  the 
real time.  But it does not establish any precise notion of time. 


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