As part of your consulting assignment with the security staff of a local company
ID: 2247564 • Letter: A
Question
As part of your consulting assignment with the security staff of a local company, you have been asked to explain the Advanced Encryption Standard (AES), Data Encryption Standard (DES), and Triple DES (3DES). Prepare a presentation that consists of 8–10 slides to explain these terms. Your presentation should fully explain these concepts in the speaker notes and should answer the following questions:
What are AES, DES, and 3DES?
How does DES work?
Why is 3DES now used?
What is the future of 3DES?
If three keys K1, K2, and K3 were used to perform 3DES encryption and K1=K3, how many independent keys were actually involved? Why?
What is a nonce?
What is a key distribution center?
Be sure to reference all sources using APA format.
Explanation / Answer
Answer:
1)AES:
The Advanced Encryption Standard (AES) is a symmetric-key block cipher algorithm and U.S. government standard for secure and classified data encryption and decryption.
In December 2001, the National Institute of Standards (NIST) approved the AES as Federal Information Processing Standards Publication (FIPS PUB) 197, which specifies application of the Rijndael algorithm to all sensitive classified data.
The Advanced Encryption Standard was originally known as Rijndael.
Advanced Encryption Standard, a symmetric 128-bitblock data encryption technique developed by Belgian cryptographers Joan Daemen and Vincent Rijmen. The U.S government adopted the algorithm as its encryption technique in October 2000, replacing the DES encryption it used. AES works at multiple network layers simultaneously. The National Institute of Standards and Technology (NIST) of the U.S. Department of Commerce selected the algorithm, called Rijndael (pronounced Rhine Dahl or Rain Doll), out of a group of five algorithms under consideration, including one called MARS from a large research team at IBM.
While the terms AES and Rijndael are used interchangeably, there are some differences between the two. AES has a fixed block size of 128-bits and a key size of 128, 192, or 256-bits, whereas Rijndael can be specified with any key and block sizes in a multiple of 32-bits, with a minimum of 128-bits and a maximum of 256-bits.
DES:
The Data Encryption Standard (DES) is an outdated symmetric-key method of data encryption.
DES works by using the same key to encrypt and decrypt a message, so both the sender and the receiver must know and use the same private key. Once the go-to, symmetric-key algorithm for the encryption of electronic data, DES has been superseded by the more secure Advanced Encryption Standard (AES) algorithm.
The data encryption standard (DES) is a common standard for data encryption and a form of secret key cryptography (SKC), which uses only one key for encryption and decryption. Public key cryptography (PKC) uses two keys, i.e., one for encryption and one for decryption.
3DES:
Triple Data Encryption Standard (DES) is a type of computerized cryptography where block cipher algorithms are applied three times to each data block. The key size is increased in Triple DES to ensure additional security through encryption capabilities. Each block contains 64 bits of data. Three keys are referred to as bundle keys with 56 bits per key. There are three keying options in data encryption standards:
Key option #3 is known as triple DES. The triple DES key length contains 168 bits but the key security falls to 112 bits.
2)How does DES work?
Answer:
DES is the original block cipher used throughout industry. It is designed to take a fixed-length string of plaintext and convert or transform it into ciphertext after conducting a series of operations. Once transformed, the resulting text is the same length as the input text to the cipher. DES is designed to work on text in 64 bit blocks. Additionally, the DES key is also 64 bits in length; however, 56 of the bits are used by the algorithm with the remaining 8 bits reserved for parity checking and then discarded making the effective key length of the algorithm 56 bits.
3)Why is 3DES now used?
Answer:
Triple DES is advantageous because it has a significantly sized key length, which is longer than most key lengths affiliated with other encryption modes. However, the DES algorithm was replaced by the Advanced Encryption Standard by the National Institute of Standards and Technology (NIST). Thus, the Triple DES is now considered to be obsolete. Yet, it is often used in conjunction with Triple DES. It derives from single DES but the technique is used in triplicate and involves three sub keys and key padding when necessary, such as instances where the keys must be increased to 64 bits in length. Known for its compatibility and flexibility, software can easily be converted for Triple DES inclusion. Therefore, it may not be nearly as obsolete as deemed by NIST.
Triple DES encrypts input data three times. The three keys are referred to as k1, k2 and k3. This technology is contained within the standard of ANSIX9.52. Triple DES is backward compatible with regular DES
4)What is a nonce?
Answer:
A nonce is a type of data bit identification in IT security and other types of technical systems. It is a number or other data variable that is used only once.
The nonce can be characterized as a "throwaway" bit of data that is a placeholder for specific security strategies. One major use is in authentication, where the nonce simply enumerates duplicate or identical data transmissions. For example, when duplicate transactions would have a negative effect on a system, the nonce makes the message unique, so that the system invalidates future messages with the same content.
5)What is a key distribution center?
Answer:
A key distribution center (KDC) in cryptography is a system that is responsible for providing keys to the users in a network that shares sensitive or private data. Each time a connection is established between two computers in a network, they both request the KDC to generate a unique password which can be used by the end system users for verification.
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