Re: A link to attempt of an attack on AES

Tom St Denis wrote:

Third, related keys implies an attacker can observe traffic with keys
that are related. Explain to me how AES is used normally that would
make it vulnerable to related key attacks. That's the point of my
question. Do you even know how ciphers are used today? How can you
suggest "fixes" to things you don't even get how they work anyways?
(and thus the useless cycle of MKS replies is continued...)

That the scenario assumed by the authors of the particular paper cited
is fairly unrealistic, is admitted by the authors themselves. My
critique is that there is 'another' way of seeing that the effort is
futile, because, even assuming they could under their assumed favourable
condition get a key, if each key encrypts only one block, then the cost
in getting the key is not economically justifiable for the return is
too little. This consideration applies evidently to other attempts of
obtaining encryption keys. If an algorithm is so safe that no attacks
can ever succeed, then using one single key (for ever) is certainly
prefectly o.k. But, assuming that there is a certain probability of
some attacker's success, using a single key would mean that then the
whole message is revealed. If dynamic keys are used, the attacker has
to work out all the different keys being used. If there are n keys
used, he has to do n times as much work. That's an essential difference
that could evidently be decisive in practice for his success or failure
in decrypting the message. This should be trivially evident.

M. K. Shen
.

Relevant Pages

  • Re: A link to attempt of an attack on AES
    ... as using a single key in the tranditional way. ... have a funny cipher. ... could have "certain" chance of success. ... of pairs (assumed available by the methods of attacks) and it would ...
    (sci.crypt)
  • Re: Bushs presidency a success?
    ... thinks the presidency will be a success. ... According to Kristol, the two greatest successes during GWB's administration are 1) the absence of attacks on US soil after 9/11, and 2) the economy. ... your neoclowns are warning us of impending al Qaeda attacks ...
    (alt.politics.bush)
  • Re: Vanderkitten
    ... That explains a lot of their recent success. ... Pooley bested an excellent field, including climber Nicole Brandli, Marianne ... number of smaller attacks on the climb, ... Don't forget other stellar riders in the field ...
    (rec.bicycles.racing)
  • Re: Timing of active defenses
    ... GURPS has you declare a defense only after you know an attack's ... Say you are getting attacked four times in a certain time period, and have the ability to actively defend against two of those attacks. ... But changing to declaring defense before rolls are made, odds are you'll defend against one blow that wouldn't have landed, and against one that would, you'll still block that one only half the time, so you're now letting one and a half blows in. ... and particularly that the effectiveness of multiple attacks with a lower chance of success is raised versus a few attacks with a high chance of success. ...
    (rec.games.frp.gurps)
  • Re: Bushs presidency a success?
    ... The anthrax attacks are somehow never counted. ... Read the article and then put the anthrax attack in and explain how that means the Bush presidency is a failure or success. ...
    (alt.politics.bush)