Notes

Many shores, for instance, have oyster reefs that act as incredibly efficient natural coastal buffers. They are able to both redirect the wave energy and absorb up to 75 percent of it.

one of the simplest forms of substitution is called the Caesar shift cipher, so named because it was favored by Julius Caesar himself. It works by using the standard alphabet but shifting the letter it begins on by a set number of characters. So, if you shifted the alphabet three places then A=D, B=E, C=F and so on.

The other method, substitution, is a system wherein one letter stands for another. For instance, A=V, B=X and so on until every letter of the alphabet has a substitute pair, thereby forming a cipher alphabet. Since this process forms an alphabet that replaces the conventional one, it is referred to as a monoalphabetic cipher.

The result was cryptography, a field that simultaneously developed two distinct branches: transposition and substitution.