hi friends, i dont really get this, please can anyone answer for once:
What is the diference between Zerocoin and Zerocash
What is more anonymous, Darkcoin, Zerocoin, or Zerocash, or Bytenote and its forks? what about Darkwallet?
If you were like I dont know... Julian Assange or someone like that and you had to send some money and your life depended on it, and the only way was via a cryptocurrency... what crypto would you use? thats the question. Whatever brings more anonimity wins big time in long run!
Here is the short answer (to the best of my knowledge):
Zerocoin (original paper): User 1 "buys" zerocoins, and this transaction can be seen by everyone, including the amount. When user 1 spends the zerocoins to user 2, the amount can be seen by everyone, but it is cryptographically impossible to link user 1 and 2.
Zerocash (new paper): In addition to breaking the link between user 1 and 2, as in the original zerocoin paper, this also hides the amount of money being transferred. This protocol also allows to transfer a zerocash coin directly to the second user without having to redeem it in the base currency, as well as split and merge zerocash coins. What is bound to cause confusion is that the authors are calling the coins in zerocash "zerocoins", just like in the original paper, even though they are not the same thing.
Darkcoin: They use a modification of CoinJoin, which they call "darksend". This is a simple coin mixing service. However, given the limited number of coins that are mixed, as well as other problems, such as with change and trust, it is possible to de-anonymize at least some transactions if you really tried to.
CryptoNote coins: User 1 sends user 2 money, but the transaction is signed by X users in a ring signature. User 2 receives money, which is visible on the blockchain with the amount, but all that can be said is that it came from one of the X members that participated in the "ring signature". The amount of anonymity increases as the number of members in the ring signature increases. For low values of X, it is possible to de-anonymize some types of transactions by a block chain analysis.
Darkwallets: Not sure. I think that this is just CoinJoin for Bitcoin. These exist only because Bitcoin refuses to implement suitable privacy measures.
So, if you had to rank them: Zerocash is the most anonymous, Zerocoin (original) is next, Cryptonote is close behind, and Darkcoin and Darkwallets are poor-man alternatives. All are better than nothing.
Nevertheless, you need to put this is perspective and consider some practical aspects: Darkcoin is working, CryptoNote coins are working but with no graphical interface, Zerocoin (original) does not exist now and will likely be implemented in Anoncoin in about 1 month, and the authors of Zerocash claim that it will be released in 3-6 months. It is possible that another existing coin will implement zerocash first (such as Anoncoin, after they release their implementation of Zerocoin). In terms of practicalities, Darkcoin is easy to use, whereas for the others, you either need to set up some parameters (such as the number of signatures in a ring signature), or make an intermediate step by buying zerocoins.
I should note that another aspect of anonymity is hiding the physical location (i.e., IP number) of where the transactions took place. Anoncoin allows users to send their transactions via i2p, which effectively hides your IP number, and it is the only coin that supports i2p to my knowledge. I think that most coins allow you to send transactions via TOR (which would achieve the same thing), but this is not set up by default, and I couldn't get this to work on my computer after 30 minutes, so I gave up.
There are potential problems with zerocash (the paper was just published): you need to trust someone to set up the initial, one-time, secret parameters and then forget them (there is a trick to fix this in zerocoin); you also can not count the number of zerocash coins as the amount is hidden. There is thus a scary possibility that someone could break the code (or learn the secret parameters), that would allow them to mint coins without anyone ever finding out. This would have the effect of inflation.
Finally, people tend to forget that it is extremely difficult to achieve anonymity when you convert any cryptocurrency for fiat: Banks and exchanges will always be the weakest link as long as fiat is the "default" currency.
If I made any mistakes, please correct me.