The right to encrypt - unlike the current debate over a right to healthcare - is a negative right: All men are born able to encrypt (given the math), it can only be taken away.

Positive rights, like healthcare or Social Security, are a thing that you are not born with that is given to you. The government does not have to provide you with encryption software in order for you to encrypt.

That is to say, I think you are correct and that right does exist.