Re: Ripple/Stellar Consensus System May Have Serious Issues as Stellar Forks

On 7 December 2014 at 20:15, Evan Schwartz <evan@ripple.com> wrote:

> Sharing thoughts from Ripple Labs on the issue: https
> <https://ripple.com/why-the-stellar-forking-issue-does-not-affect-ripple/>
> ://
> <https://ripple.com/why-the-stellar-forking-issue-does-not-affect-ripple/>
> ripple.com
> <https://ripple.com/why-the-stellar-forking-issue-does-not-affect-ripple/>
> /
> <https://ripple.com/why-the-stellar-forking-issue-does-not-affect-ripple/>
> why-
> <https://ripple.com/why-the-stellar-forking-issue-does-not-affect-ripple/>
> the-stellar-forking-issue-does-not-affect-ripple
> <https://ripple.com/why-the-stellar-forking-issue-does-not-affect-ripple/>
> /
> <https://ripple.com/why-the-stellar-forking-issue-does-not-affect-ripple/>
>
> "The Stellar Development Foundation (SDF) which maintains Stellar, a
> network built on a modified version of the Ripple code base, recently
> published a post claiming flaws in the Ripple consensus algorithm. We take
> any reports about possible security issues very seriously and after
> reviewing the information conclude that there is no threat to the continued
> operation of the Ripple network."
>
Feedback on ripple the consensus algorithm has come up before on this list.

[[

I think everything *except* the consensus algorithm is terrific. The
consensus algorithm though, in my opinion, is completely nonsensical and no
one seems to be allocating any attention to it. The problem is not with the
algorithm itself, but with the assumptions about what parties are chosen to
participate.

]]

http://lists.w3.org/Archives/Public/public-webpayments/2013Nov/0041.html

I'm unsure all these concerns were addressed on this list, perhaps the
subsequent release of the ripple white paper [1] may hold some answers

[1] https://ripple.com/consensus-whitepaper-released/.



> On Dec 6, 2014 3:40 PM, <stan.stalnaker@hubculture.com> wrote:
>
>> The fork is a result of a long delay in a transaction block clearing,
>> after which the consensus network decides it is not valid and ignores it
>> when it finally does "unexpectedly" clear. The choice is between freezing
>> the network to wait for the slow block to clear, or to decide to
>> collectively move on. It's been a theoretical issue since inception but
>> this is the first time it's actually happened IRL. The solution is to
>> lengthen the clearing time in a situation like this, slowing the network
>> but reducing the fork risk.
>>
>>
>> It's time for a new kind of money: Ven.VC
>>   Original Message
>> From: Manu Sporny
>> Sent: Saturday, 6 December 2014 23:06
>> To: Web Payments
>> Subject: Re: Ripple/Stellar Consensus System May Have Serious Issues as
>> Stellar Forks
>>
>> On 12/06/2014 05:20 PM, Melvin Carvalho wrote:
>> > Interesting article here
>> >
>> >
>> http://www.coinsetter.com/bitcoin-news/2014/12/06/ripplestellar-consensus-system-may-serious-issues-stellar-forks-1969
>>
>> This has some interesting info:
>>
>>
>> https://www.stellar.org/blog/safety_liveness_and_fault_tolerance_consensus_choice/
>>
>> """
>> This week, we discovered the first instance of a consensus failure. On
>> Tuesday night, the nodes on the network began to disagree and caused a
>> fork of the ledger. The majority of the network was on ledger chain A.
>> At some point, the network decided to switch to ledger chain B. This
>> caused the roll back of a few hours of transactions that had only been
>> recorded on chain A. We were able to replay most of these rolled back
>> transactions on chain B to minimize the impact. However, in cases where
>> an account had already sent a transaction on chain B the replay wasn’t
>> possible.
>> """
>>
>> I can't seem to find any documentation on the actual set of parameters
>> that would cause a ledger fork to happen. Anyone have a link to a
>> mathematical formula where it was proven/theorized that the event would
>> happen?
>>
>> -- manu
>>
>> --
>> Manu Sporny (skype: msporny, twitter: manusporny, G+: +Manu Sporny)
>> Founder/CEO - Digital Bazaar, Inc.
>> blog: The Marathonic Dawn of Web Payments
>> http://manu.sporny.org/2014/dawn-of-web-payments/
>>
>>
>>
>>