The Titanic was supposed to be unsinkable too. IMHO there is no level of encryption that can't be cracked given enough time and desire. Right now I would say this type of communication would be very secure, but to think it will always stay secure would be foolish.
IMHO there is no level of encryption that can't be cracked given enough time and desire.
256-bit AES is virtually unbreakable. A 256-bit cypher offers 2^256 of possible keys. If you had the computer horsepower to test 1 trillion keys every second (using a typical brute force attack) then it would take 3.67^52 years to exhaust 1% of the total keyspace.
There have been contests to break encryption. Check out distributed.net
The results from their 64-bit challenge are as follows:
It took 1,757 days for 331,252 people to test 15,769,938,165,961,326,592 keys. The peak rate was 270,147,024 kkeys/sec. The equivalent computer horsepower to check that many keys was 45,998 2GHz AMD Athlon XP machines.
They started another contest in 2002 to break a 72-bit key. It's still going.