How does Ripple solve the sock-puppet problem during consensus?

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How would such an attack work? Presumably, there would have to be a first consensus that agreed on one transaction and then a later consensus that agrees on the other transaction. Otherwise, nobody would rely on the first transaction having been accepted and there would be no attack.

But what do they do about that first consensus? If they participate in it, they've now validated both transactions. Everyone would have absolute proof they were liars, so nobody would care that they validated the second one.

If they don't participate in it, then everyone would have absolute proof that they validated a transaction that conflicted with a transaction that was previously accepted. Again, everyone would have absolute proof they were liars.

Maybe you're thinking they might try to go back and claim that the first consensus actually went down a different way than it actually went down, presenting a conflicting view of the past. The problem is, information about the past is...

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The details are very complex, but the core concept is fairly simple. Ripple solves the double-spend problem by consensus.

The analogy I use is an "agreement room". To walk into the room, you have to agree with everyone who is already in there. If you want to disagree, you have to leave and form your own room. Everyone who is honest wants to get into the biggest room they can with the most people in it.

In the room, people constantly agree on the current state of the system. It's implemented as a hash tree, so that's just one 256-bit number.

To perform a transaction, you walk into the big room and read out the transaction. Everyone checks the transaction against their ledger. Assuming there's no conflicting transaction or other problem, everyone agrees that the transaction is valid and they include it in the set of transactions they believe should be applied.

They then work on any disagreements they have by an avalanche process. Essentially, if someone is...

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If the Ripple network splits in half, then each half will validate ledgers independently, potentially with conflicting transactions. If all servers are properly configured, they will not accept any of these ledgers as fully validated, since none of them will have sufficient validations. It's possible both sides will think they're in the minority (if the split is close to 50/50).

This reflects a basic Ripple design principle -- don't tell people they can rely on results if the results are unreliable. If conditions make reliable operation impossible, it is preferable not to operate than to give people results they cannot rely on. Ripple is designed to detect these kinds of conditions.

When the network rejoins, servers will see the other ledger chain. They will gradually avalanche to the chain with more validations until one chain or the other has a super-majority of trusted validators. At that time, the network is back in agreement and everyone can again rely on the...

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Consensus is the process by which transactions (changes to the ledger) - such as payments and trades - are confirmed and consequently applied to the distributed Ripple database. The Ripple network of servers distributed across the world agrees on the transactions to be applied to the Ripple ledger in every consensus cycle. The Ripple ledger is the ground truth of the network and contains all participants' accounts with balances, exchange offers (in case they want to trade currencies) and trust lines (users can hold balances from banks and other entities or people they trust).

In order to understand the consensus process in detail start by reading this:

Reaching Consensus in Ripple

The Ripple Ledger Consensus Process

Ripple Labs' Understanding Consensus video:


Consensus components:
Timing: A consensus window starts whenever there are unconfirmed transactions or whenever more than a fixed amount of time has passed from the last consensus...
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As you probably know, the first protocol to solve the double-spend problem without a trusted third party was Bitcoin, and it did it via Proof of Work. Bitcoin's Proof of Work is considered secure because it has already been widely exposed to attacks, proving to be robust.

Ripple's Consensus is an alternative solution to the double-spend problem without a trusted third party, which uses a peering method to confirm transactions, instead of Proof of Work. The Consensus process, as part of the Ripple codebase, has been widely examined by Ripple Labs' security experts and reputable external white hat hackers (according to Ripple Labs employees' comments on the Ripple forum). So, in principle, it seems to be reliable.

It is impossible to definitely prove that something is fully secure. The absence of security breaches during a long period of time is the best evidence that a system is secure. Further exposure in the near/medium term will confirm (or not) Ripple's robustness....

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Easy to use, Sock Puppets iPad app allows younger students to explore creative storytelling. With Sock Puppets for iPad, students can create puppet shows that review vocabulary, model behavior, relate history or science facts, express their feelings, or simply retells a story. Socket puppet shows help children develop language skills, imagination, problem solving, and creative thinking.

Sock Puppets for iPad is an adorable app that lets you create sophisticated little sock-puppet shows . . . and it’s impossible not to have fun using it. There’s a free version and a paid version called Sock Puppets Complete that comes with additional content and longer recording time. Both are available in the App Store.

Create puppet shows by selecting puppets and positioning them on a stage with backgrounds and props. Tap the Record button and start talking. Tap one of the puppets, and it will lip-sync while also applying a cute little cartoonish effect to the audio of your...

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DEFINITIONS

A major goal of education is to help students learn in ways that enable them to use what they have learned to solve problems in new situations. In short, problem solving is fundamental to education because educators are interested in improving students' ability to solve problems. This entry defines key terms, types of problems, and processes in problem solving and then examines theories of problem solving, ways of teaching for problem solving transfer, and ways of teaching of problem solving skill.

What is a Problem? A problem exists when a problem solver has a goal but does not know how to accomplish it. Specifically, a problem occurs when a situation is in a given state, a problem solver wants the situation to be in a goal state, and the problem solver is not aware of an obvious way to transform the situation from the given state to the goal state. In his classic monograph, On Problem Solving, the Gestalt psychologist Karl Duncker defined a problem as...

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Help your toddler make an old sock into a new friend. It's an activity that encourages creative and imaginative play as well as concentration.

Good for age: 26 months (but older and younger kids might enjoy it, too!)

Skills developed: fine motor skills, talking, social skills


What you'll need:

felt pens and two clean, light-coloured socks - one for each of you to make into a puppet

What to do:

Put a sock on one of your hands and help your toddler to do the same. Show him how to move his thumb and fingers so that the end of the sock puppet works like a mouth. Decide on names and characters for the sock puppets. They could be people or animals (snakes are always a good choice). Use the felt pens to draw on eyes, nose and mouth. Let the two of them have a conversation, or have your sock puppet ask your toddler's puppet some questions. They might even want to sing a song together.

Last month's activities | More activities for 26-month-olds | Next...

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See also: Wikivoyage talk:Checkuser

Policy?[edit]

Wikivoyage has not in the past had any significant problem with sock puppets, especially as we are open enough to ignore them, and because we do not employ majority rule anywhere on site.

Unfortunately, we are having a rather novel problem right now, not with necessarily a single user running multiple accounts, but rather a business running multiple accounts, for the ostensible purpose of advertising and spam. These accounts also make some good proofreading edits (although they all make the same mistakes with proper nouns), but their userpages attempt to mimic that of an actual traveler, plus loads of links to the business' site.

This strikes me as something we should not simply tolerate, despite our wide leniency with policy violations within userspace. I favor a policy where we blank user pages belonging to one business that are being used for the purpose of spam and advertising. --(WT-en) Peter...

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The Amendments system provides a means of introducing new features to the decentralized Ripple consensus network without causing disruptions. The amendments system works by utilizing the core consensus process of the network to approve any changes by showing continuous support before those changes go into effect. An amendment normally requires 80% support for two weeks before it can apply.

When an Amendment has been enabled, it applies permanently to all ledger versions after the one that included it. You cannot disable an Amendment, unless you introduce a new Amendment to do so.

Background

Any changes to transaction processing could cause servers to build a different ledger with the same set of transactions. If some validators (rippled servers participating in consensus) have upgraded to a new version of the software while other validators use the old version, this could cause anything from minor inconveniences to full outages. In the minor case, a...

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