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While attacks against the basic building blocks of cryptosystems (like the SHA256 hash or AES block cipher) are rare, the protocols built upon those blocks can
by limmeau 15y ago
While attacks against the basic building blocks of cryptosystems (like the SHA256 hash or AES block cipher) are rare, the protocols built upon those blocks can be independently vulnerable.
Take the Needham-Schroeder public key protocol from 1979, for example. http://en.wikipedia.org/wiki/Needham-Schroeder_protocol#The_public-key_protocol http://en.wikipedia.org/wiki/Needham-Schroeder_protocol#The_... . It's simple and "obviously" foolproof, but a vulnerability was published in 1995, 16 years later.
Right now, we don't know if the bitcoin protocol has such a flaw. However, if it turns out to have an exploitable flaw, the entire bitcoin network will have to switch to a new protocol, which I haven't heard described as something they have a concrete plan for.
- mike_esspe 15y agoSuch switch happened once. It was found, that due to overflow, someone issued a lot of bitcoins to themselves in the block. During several hours was released a new client, which ignored flawed blockchain. When most people moved to a new client, the new blockchain overcame the exploited one. Though it was when bitcoin wasn't popular.
- vessenes 15y agoI was (and still am) a bitcoin user during this period, it was managed relatively easily and quickly; major miners updated their clients and within a few hours, the competing blockchain had died off. This would likely be even easier to accomplish today; as things currently stand, all mining pools and groups have a vested interest in maintaining the integrity of the blockchain.