Re: [bitcoin-dev] Interpreting nTime for the purpose of Bitcoin-attested timestamps

2016-09-19 Thread Tom Harding via bitcoin-dev
On 9/19/2016 10:56 AM, Peter Todd wrote: > I should state that assumption more clearly. Glad to get you thinking, and I need to change my suggestion. The catch-up formula is not applicable because it doesn't limit how long the dishonest miners have to catch up. Instead you want the probability t

Re: [bitcoin-dev] Interpreting nTime for the purpose of Bitcoin-attested timestamps

2016-09-19 Thread Peter Todd via bitcoin-dev
On Mon, Sep 19, 2016 at 09:13:40AM -0700, Tom Harding via bitcoin-dev wrote: > > On 9/17/2016 9:20 PM, Peter Todd via bitcoin-dev wrote: > > The probability that all N blocks are found by dishonest miners is q^N, > > That's the probability that dishonest miners find N blocks in a row > immediatel

Re: [bitcoin-dev] Interpreting nTime for the purpose of Bitcoin-attested timestamps

2016-09-19 Thread Tom Harding via bitcoin-dev
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 9/17/2016 9:20 PM, Peter Todd via bitcoin-dev wrote: > The probability that all N blocks are found by dishonest miners is q^N, That's the probability that dishonest miners find N blocks in a row immediately. What you want is the probability that

Re: [bitcoin-dev] Interpreting nTime for the purpose of Bitcoin-attested timestamps

2016-09-18 Thread Peter Todd via bitcoin-dev
On Sun, Sep 18, 2016 at 03:45:40PM +0200, Jannes Faber wrote: > Would you not also have to consider (all) earlier blocks? > > T = max(block[i].nTime for i in {x-100, ..., x, ..., x + N-1}) + max_offset > > In case one or more previous blocks have an nTime considerably in the > future and blocks>=

[bitcoin-dev] Interpreting nTime for the purpose of Bitcoin-attested timestamps

2016-09-17 Thread Peter Todd via bitcoin-dev
As part of my recent work(1) on OpenTimestamps I've been putting some thought towards how to interpret the nTime fields in block headers, for the purpose of timestamping. I'd like to get some peer review on the following scheme I've come up with. # Motivation We want to use the Bitcoin blockchai