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http://en.wikipedia.org/wiki/DES#Vulnerabilities "...a corporation willing to spend 10 million dollars to build a similar device today might break DES dozens if not hundreds of times per hour." I do not know of any more examples other than the few listed in the article in 1999. Peter Curran wrote: >I think that there are 2 different issues here. > >1. PBKDF1 (and similar) algorithms (such as the one used by Kerberos - ISTR >this is a different way of doing the same thing) are really designed at >producing a good quality key with minimal entropy. The idea being that a >simple brute-force attack on the whole key space is not 'short-cuttable'. >Whilst they may be successful in achieving that objective, they will not help >if the user selecting the password chooses a weak example, such as a >dictionary word, car registration number or similar. (I know that you made >the caveat about 'usual precautions', but the reality is that these are >broadly ignored/unenforceable). > >2. 56 bit DES tends to be dismissed as 'too weak'. Well, I don't know if >you have any knowledge of anybody ever having any DES-encrypted data >compromised by a brute force attack - I certainly don't. [password guessing, >on the other hand, is sadly familiar]. As you say, a couple of PC's are not >going to help much when it comes to attempting a brute-force attack on a >56-bit DES encryption. I think it is a shame that it has become received >wisdom that anything with a key length < 128 bits is bad. For your average >man in the street, 56-bit DES is perfectly adequate and likely to remain so >for a few years yet. (I had this problem a few days ago when trying to >explain to a company that using plain DES to support Windows/UNIX integration >using Kerberos was OK). They just did not accept it! Why, because they had >seen a TV programme where some pundit had explained that <128-bit == BAD >CRYPTO! > >Peter > >On Tuesday 06 July 2004 15:49, Manuel Kasper wrote: > > >>On 06.07.2004 15:25 +0100, Peter Curran wrote: >> >> >>>I think encyrption is intriguing as a solution to the >>>confidentiality issues, but as they are using DES on the Netgear >>>stuff I assume that you have to pre-configure all the devices with >>>a shared key. As this tends to be derived from a passord it could >>>be relatively easy to attack. >>> >>> >>I did a little analysis of HomePlug powerline networking about a year >>ago. The password hashing is done as per PBKDF1 - it involves using >>MD5 1000 times, so with the usual password precautions in place, the >>resulting 56-bit DES key should be good. Also, provided that the >>implementation in HomePlug doesn't suffer from similar flaws as WEP, >>56-bit encryption is IMHO enough for home users. I mean, it's not >>like you can brute-force-search a 56-bit key in a useful amount of >>time with only a few PCs at hand... >> >>- Manuel >> >> > > > > |