[RC5] Do not forget about the cheaters :)
rawkiw at cix.co.uk
Thu Jan 8 08:19:57 EST 2004
This is a nice tweak, clearly the number of bits will have to make
"collisions" reasonably likely, for some reasonable value of reasonable.
(I think the overhead is the pre -calcualtion by the server so this works
In turn this means that you could send some random bits, and only do a
check on a random basis on the answers returned.
Early abort would not work against this in the long run as a cheater would
have a lower average number of returns per block.
(Conversely both your system and my system make it near impossible to
"safely" cheat on a single block, although mine suffers from the "kind
tract.pdf) paradox according to the number of dummy keys.)
From: Decio Luiz Gazzoni Filho [SMTP:decio at revistapcs.com.br]
RSA-provided cyphertext with this key, and extract [...]x bits. x is a
parameter that allows you a tradeoff between
overhead (mainly communication) and probability of catching a cheater. Now
you ask the client to return *all* instances of cyphertext matching the
this is very resilient to an early-abort strategy [...]
This mail has been checked for viruses, by Richard, but you should ensure
your system check all incoming mail itself.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.532 / Virus Database: 326 - Release Date: 27/10/2003
More information about the rc5