Quote from: r.willis on April 11, 2013, 12:02:53 PM

Bitcoin has proven track record. Does ripple?

Not yet.

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Is there whitepaper about mechanisms ripple use?

There a wiki and I'm happy to answer any questions. https://ripple.com/wiki

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Is it opensource?

The client is. The server will be as soon as it's stable enough.

We are already signing every ledger and publishing every transaction. Every transaction is signed by the account holder. Every change in the ledger (the set of all account states) is justified by a transaction. If we were to cheat in any way, this would be trivially provable. There would be one ledger with the previous data and one with the cheating data, and we would have signed both of them, and there would be no valid transaction justifying the change.

Again, we sign every new ledger, about every 20 seconds. Each ledger also includes hashes of previous ledgers. So say we modified a ledger so that some balances were changed. There would be the ledger before we changed it, signed by us. And there would be the ledger after we changed it, signed by us. And in the ledger would be the tree of transactions. If there was a valid transaction that explained the change, it would be legitimate. If not, that would be trivially demonstrable. We simply *can't* cheat and get away with it.

http://pastebin.com/R7i9DYZj
This is an example of a published transaction, included in a signed ledger. It is signed by the account that generated it. And it includes metadata that shows every node in the ledger it changed and precisely how it changed it. No changes to balances, offers, or the like are ever made without this type of justification. And if such a change ever was made, it could easily be shown beyond doubt.

We designed the system so that people would have good reasons to trust it without needing a central authority to trust.

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How emission is managed?

I don't know what you mean.

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How it's protected from double-spends?

By consensus. Here's the simplest explanation:

Think of a room full of people who all agree with each other. To enter the room, you must agree with them. To disagree with them, you must leave the room. They all sit in this room maintaining continuous agreement on everything. Each of them who is honest puts their first priority on enforcing the rules of the room, their second priority on maintaining agreement with everyone who is also willing to follow the rules, and their third priority on accepting legitimate transactions provided they don't violate the first two rules. The rules of the room make it infeasible to agree to a transaction once a conflicting transaction has been agreed to -- such an agreement cannot be formed and be valid according to the rules.

Essentially, to perform a transaction, you walk into the room and read out the transaction. Every honest person in the room agrees the transaction is valid. They then follow a set of deterministic rules to apply the transaction to the ledger (the state of every account), form the new ledger, and each person in the room signs the hash of the new ledger, which they now agree on. Anyone who tries a double spend will find their transaction won't fit in the ledger because a conflicting transaction already has.

If both transactions appear at about the same time, a deterministic rule decides which one wins.

A transaction is considered validated once it's included in a ledger that has been signed by the majority of people in the room.