краткий пересказ. (Historical Cryptography) (краткий пересказ. (Historical Cryptography).docx)

Historical Cryptography

1. How does the substitution cipher work?

Substitution is any cipher system, which substitutes one symbol or character for another.

1. What is a Scytale?

Scytale is a device used to send and receive secret messages. It was a cylinder with narrow strip of parchment rounded around. After some secret was written on the parchment and afterward, it was taken off the cylinder. For decryption of such message, you need to use the same cylinder.

1. What is a transposition cipher?

Transposition cipher is a cipher system, which changes the order of the characters instead of changing the characters instead.

1. What idea underlies the Vegenere Cipher?

The Vegenere Cipher works exactly like the Caesar except that it changes the key according to secret word throughout the encryption process.

1. Why is it more difficult to break the code based on a unique language?

Codes based on a unique language must be studied extensively before beginning to decode them. I do not know why it is like that and there is no such information in the text.

1. What is the Enigma known for?

Enigma is an electro-mechanical machine that was used for encryption and decryption of secret messages. Enigma was virtually unbreakable with brute force methods. It was widely used by Germany in World War.