Cryptography Question (I hope it's not off-topic on this list)

I was thinking about *chaining* remailers and wondered if encryption of a certain strength could be *chained* in order to make it as strong as stronger encryption. e.g. - If only 56-bit encryption becomes legal, is there a method of *chaining* several passes of 48-bit encryption which would make it just as hard to break as 96/192/384-bit (etc.) encryption? If this is indeed impossible, then perhaps the government might pass a law that makes it illegal to encrypt an encrypted file, but experience seems to suggest that any law passed always leaves a loophole or back door for inventive people to circumvent it. CyberDoc