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Well, it can be argued that any security feature can be circumvented in theory, which is why super-secure networks are fond of air gaps. The NX bit isn't really
by jspthrowaway2 14y ago
Well, it can be argued that any security feature can be circumvented in theory, which is why super-secure networks are fond of air gaps. The NX bit isn't really an air gap, just like ASLR, DEP, and so forth.
The features of a processor designed to protect itself from memory are really just stop gaps on the way to the next paradigm that supplants von Neumann, is I think what Watson is saying.
- pretoriusB 14y ago>Well, it can be argued that any security feature can be circumvented in theory I don't think that can be argued.
- DanBC 14y agoSure it can. Do you have any examples of security features which are theoretically uncircumventable?
- pretoriusB 14y agoNo, but I have the certainty that you cannot prove that "every security feature is circumventable". They might be, or they might no be. But in no "theory" it is proven that this is so. So I don't see how someone can argue that "in theory everything is circumventable".
- DanBC 14y agoOkay, this is just a linguistic thing then. Two examples: 1) We think (but have not proved) that factoring large numbers is hard. We use this for cryptography. In theory the crypto could be brute forced, or maybe find some new method for factoring. In practice brute forcing would take longer than the Universe will exist and there is unlikely to be a breakthrough in factoring large numbers. 2) We think that a single overwrite of a hard disc platter is enough to destroy the information. No software exists that claims to be able to recover information that has bee over written once. No companies exist that claim to be able to recover data that has been over-written once. No university research exists showing recovery of data that has had a single overwrite. No criminals have been prosecuted or convicted with evidence recovered from a disc that's had a single overwrite. Everything we know suggests that a single overwrite is fine. But, because a well funded government might be able to recover that data we suggest that people do 3 (or 8, or 30something if you're being silly) over writes, or if the data is really important that people destroy the platters. In theory the data might be recovered, and so people have decided that in practice they will destroy the drive or overwrite more than once. When talking about security it's a good idea to assume that someone can break whatever you're doing, and then ask if you need to do more, or need to do things differently.
- lispilicious 14y agoOTP is unbreakable. http://en.wikipedia.org/wiki/One-time_pad http://en.wikipedia.org/wiki/One-time_pad
- dexen 14y agoIronically, One Time Pad is breakable in practice, due to mistakes made, shortcuts taken[0] and side-channel attacks[1]. Besides, it relies on securely distributing the pad itself before information exchange can take place, which in turn is prone to the usual array of physical insecurity, design errors (e.g. using publicly available randomness), or, if distributed by a digital channel, to failures of the encryption used. [0] http://en.wikipedia.org/wiki/Venona_project http://en.wikipedia.org/wiki/Venona_project [1] http://en.wikipedia.org/wiki/Operation_Gold http://en.wikipedia.org/wiki/Operation_Gold
- tjoff 14y agoQuantum key distribution is, theoretically, uncircumventable. QKD implementations on the other hand ...