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Bitcoin => Bitcoin Discussion => Topic started by: CryptoCurrencyInc.com on October 29, 2014, 08:46:19 PM



Title: Bitcoin-Over-Tor Anonymity 'Can Be Busted for $2,500 a Month'
Post by: CryptoCurrencyInc.com on October 29, 2014, 08:46:19 PM
Bitcoin-Over-Tor Anonymity 'Can Be Busted for $2,500 a Month'
http://www.coindesk.com/bitcoin-tor-anonymity-can-busted-2500-month/


Title: Re: Bitcoin-Over-Tor Anonymity 'Can Be Busted for $2,500 a Month'
Post by: Walter Rothbard on October 29, 2014, 09:25:50 PM
Basically they detail a denial of service attack to Bitcoin nodes running behind tor, by sending transactions from all known tor exit nodes until all those nodes are banned for 24 hours.

It seems to me the solution to that is to run your own Bitcoin node outside of tor and whitelist the IP address you want to connect from, or a modification to the protocol that allows transactions to be specially signed and let through even from blocked nodes.


Title: Re: Bitcoin-Over-Tor Anonymity 'Can Be Busted for $2,500 a Month'
Post by: madmadmax on October 29, 2014, 11:29:21 PM
You could compile Bitcoin from source removing its DDoS protection (since it is useless behind Tor anyway) viola, problem solved.


Title: Re: Bitcoin-Over-Tor Anonymity 'Can Be Busted for $2,500 a Month'
Post by: Ricke on October 29, 2014, 11:49:54 PM
If I'm correct, this method "clues" a torrified bitcoin client to an attacker's static IP by banning all other nodes.

Quick solution: Avoid using a single (bitcoind) setup for two identities which shouldn't get singled out as just one. Same applies to clients like Electrum.

Other solution: Signing a transaction by the client while broadcasting it through tor over pushtx. Example URL: https://blockchain.info/pushtx


Title: Re: Bitcoin-Over-Tor Anonymity 'Can Be Busted for $2,500 a Month'
Post by: scarsbergholden on October 30, 2014, 12:11:30 AM
Basically they detail a denial of service attack to Bitcoin nodes running behind tor, by sending transactions from all known tor exit nodes until all those nodes are banned for 24 hours.

It seems to me the solution to that is to run your own Bitcoin node outside of tor and whitelist the IP address you want to connect from, or a modification to the protocol that allows transactions to be specially signed and let through even from blocked nodes.
Another solution would be to not rely a transaction via tor with a full node, but rather use either blockchain.info/pushtx or a light client like multibit.

There is no real reason to need to use a full node to push a tx. You could sufficiently protect yourself by using a full node to monitor for you receiving a TX or to use a trusted block explorer that you can access via a tor hidden service


Title: Re: Bitcoin-Over-Tor Anonymity 'Can Be Busted for $2,500 a Month'
Post by: ANTIcentralized on October 31, 2014, 06:17:02 AM
You could compile Bitcoin from source removing its DDoS protection (since it is useless behind Tor anyway) viola, problem solved.
You would need to get the nodes that are operating outside of tor to remove the feature that "bans" a bitcoin node after x number of invalid transactions, this feature is necessary as a node will quickly get overwhelmed with invalid transactions