Original: Distributed.net has brute-forced RC5 messages encrypted with 56 - and 64-bit keys , and is working on cracking a 72-bit key ; as of August 2009 0.64 % of the keyspace have been searched .
Simplified: Distributed.net has brute-forced RC5 messages encrypted with 56 - and 64-bit keys , and now is working on cracking a 72-bit key .