Basic Terms to be used :

• plaintext – It is a kind of original message
• ciphertext – It is a type of  coded message
• cipher – An algorithm to be performed for transforming plaintext/ciphertext.
• key – The information used in cipher known only to sender and receiver.
• encipher (encrypt) – It means converting plaintext to ciphertext
• decipher (decrypt) – It means recovering ciphertext from plaintext
• cryptography – To study how encryption will perform with rules/methods?
• cryptanalysis (codebreaking) – It is a process to the study of principles/ methods of deciphering ciphertext without knowing key
• cryptology – The field of both cryptography and cryptanalysis

There are two kinds of ciphers:

1. Symmetric cipher

It is a single key in which Both sender and receiver have full information about the key.

2. Public key ciphers

It is very different from symmetric cipher, in which different keys are used for both encryption and decryption. In public ciphers, receiver needs to publish an encryption key, referred to as his public key.

Types of ciphers techniques:

1. Monoalphabetic Ciphers
2. Polyalphabetic Ciphers
3. Transpositions and Grills
4. Steganography
5. Morse code
6. caesar shift cipher
7. Book cipher
8. Scytale
9. Pigpen cipher
10. Playfair cipher