> That's my point. Can we make the cost and time lengthe of a successful attack to be too expensive. What's the use of a peg that is likely to break after one

> That's my point. Can we make the cost and time lengthe of a successful attack to be too expensive. What's the use of a peg that is likely to break after one year though? Symmetric ciphers are basically a solved problem until a computing revolution, this doesn't seem to be nearly as easy.