Overview#
Substitution Cipher is a method of
Encryption by which units of
plaintext are replaced with
ciphertext according to a fixed system; the "units" may be single letters (the most common), pairs of letters, triplets of letters, mixtures of the above, and so forth. Substitution Cipher keeps the the units of the
message are retained in the same sequence in the
ciphertext, but the units themselves are altered.
Decryption the text by performing the inverse substitution.
Substitution Cipher can be compared with Transposition Ciphers where the units of the plaintext message are rearranged in a different and usually quite complex order, but the units themselves are left unchanged.
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