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I disagree with the governement conspiracy thing, but the bitcoin protocol has been incredibly secure. This is pretty common knowledge. People can't "hack" into

by Kapura 14y ago

I disagree with the governement conspiracy thing, but the bitcoin protocol has been incredibly secure. This is pretty common knowledge. People can't "hack" into the bitcoin network and make themselves millionaires.

tptacek 14y ago
It is "incredibly secure" in the same sense as the banks that use TLS are using "military grade" encryption.
patio11 14y ago
Howdy Kapura. (A bit of background knowledge: It might not be obvious if you haven't been here for a while, but the guy you're talking to is something of an expert in making systems dependent on cryptography do horrible, horrible things.) It may be "common knowledge" that the bitcoin protocol is secure, but this is largely because a) most bitcoin users and advocates are not competent to make any determination of security, b) you should probably include an asterix to the claim like "Well, secure if you don't count the successful double-spend attack which necessitated a holy-shit-drop-everything-and-downgrade response by several mining pool operators", and c) acknowledge that one of the main reasons people don't attack the protocol is because Bitcoin exchanges have been coughing up everything one could possibly want, and more, with far less work. I should probably write a blog post digging into what people mean when they talk about "the Bitcoin protocol", by the way. Bitcoin isn't a protocol like HTTP is a protocol. Bitcoin's entire protocol specification is the Satoshi bitcoin client, which you have to warts-and-all emulate to be accepted by the network, because if you ever disagree with the Satoshi client about the validity of any single transaction in history then you're suddenly building off a blockchain which is incompatible with the one used by all the businesses that one would theoretically want to spend Bitcoins at. It is entirely possible for "the Bitcoin protocol" -- the series of steps by which clients agree on the status of the blockchain -- to be bulletproof while the Satoshi client (i.e. the only instantiation of the protocol that matters) to get busted like a pinata via e.g. a buffer overflow attack. One would hope that when that happens, it does not happen on every computer using bitcoin simultaneously, which strikes me as a very plausible scenario given that the designed intent of bitcoin is to fan attacker-chosen executable instructions to every node on the network.
- brian_cloutier 14y ago
  Just a few points here, although most of your comment is valid. > Well, secure if you don't count the successful double-spend attack which necessitated a holy-shit-drop-everything-and-downgrade response by several mining pool operators You're getting your history wrong. There was a problem with older satoshi clients that caused a fork in the block chain. The fork was serious enough that all miners with newer clients were asked to temporarily downgrade. There was also somebody who took advantage of that fork to create a double-spend. So, 1) The double spend was caused by the holy-shit moment, not the other way around. 2) There is no proof anybody lost money. Most big merchants stopped processing transactions during the fork, who knows if the transactions on the losing chain were accepted. > designed intent of bitcoin is to fan attacker-chosen executable instructions to every node on the network This is just fear-mongering. The intent is to create a medium of exchange between untrusted parties. There is a scripting system that used to be run by clients when checking whether a transaction output could be spent. That system has a) never been able to do much of anything except manipulate numbers and b) been disabled for quite some time now.

by Kapura 14y ago

tptacek 14y ago

It is "incredibly secure" in the same sense as the banks that use TLS are using "military grade" encryption.

patio11 14y ago

Howdy Kapura. (A bit of background knowledge: It might not be obvious if you haven't been here for a while, but the guy you're talking to is something of an expert in making systems dependent on cryptography do horrible, horrible things.) It may be "common knowledge" that the bitcoin protocol is secure, but this is largely because a) most bitcoin users and advocates are not competent to make any determination of security, b) you should probably include an asterix to the claim like "Well, secure if you don't count the successful double-spend attack which necessitated a holy-shit-drop-everything-and-downgrade response by several mining pool operators", and c) acknowledge that one of the main reasons people don't attack the protocol is because Bitcoin exchanges have been coughing up everything one could possibly want, and more, with far less work. I should probably write a blog post digging into what people mean when they talk about "the Bitcoin protocol", by the way. Bitcoin isn't a protocol like HTTP is a protocol. Bitcoin's entire protocol specification is the Satoshi bitcoin client, which you have to warts-and-all emulate to be accepted by the network, because if you ever disagree with the Satoshi client about the validity of any single transaction in history then you're suddenly building off a blockchain which is incompatible with the one used by all the businesses that one would theoretically want to spend Bitcoins at. It is entirely possible for "the Bitcoin protocol" -- the series of steps by which clients agree on the status of the blockchain -- to be bulletproof while the Satoshi client (i.e. the only instantiation of the protocol that matters) to get busted like a pinata via e.g. a buffer overflow attack. One would hope that when that happens, it does not happen on every computer using bitcoin simultaneously, which strikes me as a very plausible scenario given that the designed intent of bitcoin is to fan attacker-chosen executable instructions to every node on the network.

brian_cloutier 14y ago
Just a few points here, although most of your comment is valid. > Well, secure if you don't count the successful double-spend attack which necessitated a holy-shit-drop-everything-and-downgrade response by several mining pool operators You're getting your history wrong. There was a problem with older satoshi clients that caused a fork in the block chain. The fork was serious enough that all miners with newer clients were asked to temporarily downgrade. There was also somebody who took advantage of that fork to create a double-spend. So, 1) The double spend was caused by the holy-shit moment, not the other way around. 2) There is no proof anybody lost money. Most big merchants stopped processing transactions during the fork, who knows if the transactions on the losing chain were accepted. > designed intent of bitcoin is to fan attacker-chosen executable instructions to every node on the network This is just fear-mongering. The intent is to create a medium of exchange between untrusted parties. There is a scripting system that used to be run by clients when checking whether a transaction output could be spent. That system has a) never been able to do much of anything except manipulate numbers and b) been disabled for quite some time now.