Un primo passo sul rendere Bitcoin completamente anonimo attraverso una procedura userfriendly
La differenza con i mixer precedenti, è che il gestore del servizio/server non può scappare con i Bitcoin depositati.
Il mixer però mi pare di capire che sia ancora in grado di tenere traccia dei passaggi, semplicemente non ha più bisogno di farlo per fare funzionare l'infrastruttura.
(devo ancora capire bene questa cosa...)
Il passaggio successivo, e creare una rete p2p per rendere superfluo anche "il server dove effettuare l'incontro".
Questa tecnica dovrebbe andare bene per importi piccoli, ma non essere molto adeguata per grosse somme.
E' anche vero però, che si potrebbero far passare grosse somme dividendole nel tempo in importi piccoli.
Discussione riguardo a
coinjoin:
https://bitcointalk.org/index.php?topic=279249.0https://bitcointalk.org/index.php?topic=40264.msg3367854#msg3367854Sharedcoin trustless mixing now available for testingSharedcoin uses a technique known as coinjoin to provide coin mixing without needing to trust any third party with your funds. The service still relies on a centralised server but that server only co-ordinates transactions without any funds passing through it. The main advantages are significantly less risk risk for both the user and operator and no requirement to keep any logs.
Anyone interested in testing can login using the following link:
https://blockchain.info/wallet/login?enable_sharedcoin=truePlease test with small amounts only (0.5 BTC max). 0.1 BTC is the minimum send amount. If you experience any errors please record the output from the
javascript console.
The current client stages are:
- The client will submit its "offer", which is the inputs it wants mixing and the desired outputs.
- The server waits a certain amount of time for other clients to submit their offers.
- The server combines everyone's offers and creates a "proposal".
- The clients check they are happy with the proposal and sign their inputs.
- The server submits the final transaction.
The entire process takes about 40 seconds.
Features currently supported:
- Variable number of inputs and outputs per client
- Variable input and output values.
- Randomised fees.
- Ability to draw upon reserve funds when no other participants are available for mixing.
- Taint analysis determines the appropriate inputs to mix.
Features planned:
- Multiple iterations using temporary addresses never saved inside wallets.
- Better randomisation of change outputs and splitting of outputs between multiple iterations.
- Better progress indication.
- Documented Client APIs and SDK.
Example sharedcoin transaction:
https://blockchain.info/tx/72316782bf48d0cd232b888a7b9ea03f88ba79fac28273cd2aa1804683235412?show_adv=trueThe amount currently available in the reserve pool is low, I'll be gradually increasing this over time but during the testing phase if anyone manages to manipulate the client to withdraw excess funds from the pool they can keep that amount.
Client source available at:
https://github.com/blockchain/My-Wallet/blob/master/sharedcoin.jsServer status can be viewed while testing at:
https://api.sharedcoin.com/ 
