Revision for Chapter 4

Each encryption method uses a specific algorithm, called a cipher, to encrypt and decrypt messages. A cipher is a series of well-defined steps used to encrypt and decrypt messages. There are three methods of creating ciphertext:

• Transposition

• Substitution

• One-time pad

1st type of Encryption: _________ algorithms

Answer explanation

Symmetric algorithms - These algorithms use the same pre-shared key, sometimes called a secret key pair, to encrypt and decrypt data. Both the sender and receiver know the pre-shared key before any encrypted communication begins.

2nd type of Encryption: _________ algorithms

Answer explanation

Asymmetric algorithms - Asymmetrical encryption algorithms use one key to encrypt data and a different key to decrypt data. One key is public and the other is private. In a public-key encryption system, any person can encrypt a message using the public key of the receiver, and the receiver is the only one that can decrypt it using his private key. Parties exchange secure messages without needing a pre-shared key. Asymmetric algorithms are more complex. These algorithms are resource intensive and slower to execute.

(Cryptography)
Symmetrical versus Asymmetrical Encryption over handling more data

• Symmetric encryption

• Asymmetric encryption

List the types of encryption algorithm and provide the encryption standard for each class

• Symmetric - Triple Digital Encryption Standard (3DES)

• Symmetric - Advanced Encryption Standard (AES)

• Symmetric - International Data Encryption Algorithm (IDEA)

List the other type of encryption algorithm and

provide the various encryption standard for each class

• Asymmetric - Rivest_ Shamir-Adleman (RSA)

• Asymmetric - Diffie-Hellman

• Asymmetric - EIGamal

• Asymmetric - Elliptic Curve Cryptography (ECC)

A product consultant had recommended to his team an algorithm that

is used in New Technology File System (NTFS).

Identify the algorithm recommended by the product consultant

A product consultant had recommended to his team an algorithm that

is used in New Technology File System (NTFS).

Name the type of encryption used for the algorithm that

you have identified in the earlier question: Symmetrical / ____________

A product consultant had recommended to his team an algorithm that

is used in New Technology File System (NTFS).

Describe the encryption that you have name in the earlier question:

Answer explanation

use the same pre-shared key, sometimes called a secret key pair, to encrypt and decrypt data.

Both the sender and receiver know the pre-shared key before any encrypted communicaiton begins.

State the benefits of using Symmetric algorithms

• More efficient in handling more/larger data

• More problematic

• Harder to manage

• Easier to manage