Snake oil (cryptography): Difference between revisions
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In [[Cryptography]], the term '''snake oil''' <ref>{{cite paper|author=Bruce Schneier|title=Snake Oil | journal=Crypto-Gram Newsletter|publisher=Counterpane Inc.|date=February 1999|url=http://www.schneier.com/crypto-gram-9902.html#snakeoil}}</ref> is used to refer to various products which use ''wildly extravagant claims | In [[Cryptography]], the term '''snake oil''' <ref>{{cite paper|author=Bruce Schneier|title=Snake Oil | journal=Crypto-Gram Newsletter|publisher=Counterpane Inc.|date=February 1999|url=http://www.schneier.com/crypto-gram-9902.html#snakeoil}}</ref> is used to refer to various products which use ''wildly extravagant claims'' to market ''appallingly bad cryptography''. | ||
For examples, see [[Dimitri Sklyarov]]'s [[Defcon]] presentation [http://www.cs.cmu.edu/~dst/Adobe/Gallery/ds-defcon/sld001.htm] on e-book security. One company advertised "the only software in the universe that makes your information virtually 100% burglarproof!"; their actual encryption was "XOR-ing each byte with every byte of the string “encrypted”, which is the same as XOR with constant byte". Another used [[Rot 13]] encryption. ZDnet [http://news.zdnet.com/2100-9595_22-116424.html?legacy=zdnn] described some of these systems as "astonishingly inept cryptography software". They are ludicrously weak, utterly worthless even against an attacker who uses only pencil and paper. | For examples, see [[Dimitri Sklyarov]]'s [[Defcon]] presentation [http://www.cs.cmu.edu/~dst/Adobe/Gallery/ds-defcon/sld001.htm] on e-book security. One company advertised "the only software in the universe that makes your information virtually 100% burglarproof!"; their actual encryption was "XOR-ing each byte with every byte of the string “encrypted”, which is the same as XOR with constant byte". Another used [[Rot 13]] encryption. ZDnet [http://news.zdnet.com/2100-9595_22-116424.html?legacy=zdnn] described some of these systems as "astonishingly inept cryptography software". They are ludicrously weak, utterly worthless even against an attacker who uses only pencil and paper. | ||
Revision as of 03:16, 23 October 2008
In Cryptography, the term snake oil [1] is used to refer to various products which use wildly extravagant claims to market appallingly bad cryptography.
For examples, see Dimitri Sklyarov's Defcon presentation [1] on e-book security. One company advertised "the only software in the universe that makes your information virtually 100% burglarproof!"; their actual encryption was "XOR-ing each byte with every byte of the string “encrypted”, which is the same as XOR with constant byte". Another used Rot 13 encryption. ZDnet [2] described some of these systems as "astonishingly inept cryptography software". They are ludicrously weak, utterly worthless even against an attacker who uses only pencil and paper.
Warning signs
A few things are warning signs that a product is bogus, or at least should be treated as suspect. We cover only the most conspicuous here; for more complete lists see the references.
One indicator is extravagant claims: "unbreakable", "revolutionary", "military-grade". "hacker-proof", "breakthrough".
Another indicator is a lack of technical details or references to research literature. This violates Kerckhoffs' Principle; no algorithm can be trusted until it has been published and analysed. If a vendor does not reveal all the internal details of their system so that it can be analysed, then they do not know what they are doing; assume their product is worthless. Any reason they give for not revealing the internals can be ignored. The only exception would be a large government agency who have their own analysts. Even they might get it wrong; Matt Blaze found a flaw [3] in the NSA's Clipper chip within weeks of its internals becoming public.
References to one-time pads. Real one-time pads are provably unbreakable for certain attacks, but snake oil often claims unbreakability for things that are not actually one-time pads. There is some current research suggesting that certain techniques may offer equivalent security, but if the claim "just like a one-time pad" is made without reference to the specific research, one may be well-advised to look for a snake charmer.
External links
- Matt Curtin's Snake Oil FAQ [4] is the commonest reference.