Chapter 8, Problem 1RQ

Explanation of Solution

Cryptography and cryptanalysis:

• Cryptography is a technique to convert the plain text to cyber text to protect the data from hackers.
• Cryptanalysis is the art of study to decrypt the cyber text without knowing the key.

Cryptography:

Cryptography is a technique to encrypt and decrypt the data using keys. The user can send or receive data across insecure networks using the cryptography. This system may use same or different keys for sender and receiver.

This technique can be categorized into two types:

• Symmetric key cryptography.
• Asymmetric key cryptography.

Symmetric key cryptography:

This cryptography uses the same secret key for sender and receiver to encrypt and decrypt the message.

Asymmetric key cryptography:

The sender and receiver uses different keys for encryption and decryption. It is otherwise known as public key cryptography.

Cryptanalysis:

Cryptanalysis is a study of retrieving plain text from a cipher text without knowing the encryption key and algorithm used to encrypt it. This art used to defeat cryptographic security and gain access to the contents of encrypted messages. The cryptanalysts may responsible for following things:

• Design the security systems to prevent the vulnerabilities.
• Evaluate and analyze the security systems and algorithm for cryptography.
• Protecting critical data from being modified and deleted.