Research the Advanced Encryption Standard (AES) and the Data Encryption Standard (DES) algorithm and write two paragraphs summarizing explaining how it works with examples. A discussion question will

Advanced Encryption Standard (AES) is a symmetric block cipher which is chosen by the U.S. government to protect its sensitive government information. It is an encryption method that is accepted globally. These are presented in the software as well as the hardware in order to maintain the encryption of sensitive data. AES consists of three block ciphers: AES-128, AES-192 and AES-256. The AES algorithm is capable of using the 128, 192 and 256 bits of cryptographic keys to encrypt and decrypt data in blocks of 128 bits. AES-128 uses a 128-bit key length to encrypt and decrypt a block of messages. AES-192 uses a 192-bit key length and AES-256 a 256-bit key length to encrypt and decrypt messages (Rouse, 2020). These larger key sizes not only increase the security level, but AES can also encrypt data faster than a Triple Data Encryption Standard (DES). This is a DES enhancement which encrypts three times ("Advanced encryption standard"). The secret key is the key that the ciphers use for encryption and decryption, and the same key is used by the sender and the receiver, hence they both should know this secret key. The information is classified as confidential, secret or top secrets, and all the key lengths that are 128, 192 and 256 can be used to protect the confidential and secret level information, however the top secret information requires the higher level, i.e. 192 or the 256 bit key length to protect it. Likewise, three transformations occur where the first transformation in the AES encryption cipher is the data substitution, and the second is the shift of data rows, and the last one is the mix of columns, where different parts of the encryption key is used on each column. AES has a higher ability to resist attack, and it is intended to be released on a global basis. It is distributed non exclusively and without royalty. Likewise, the algorithm of AES is flexible, suitable for the hardware and software and it is simple (Rouse, 2020). AES is seen in our day to day lives for example in applications like WhatsApp, Signal, and programs such as VeraCrypt and WinZip. It is also used in hardwares and other technologies that we use. Under AES the plaintext, which the information that the user wants to encrypt is separated into blocks, and the block size of AES is 128 bits. Hence, it separates the data that needs to be encrypted to a four by four column of sixteen bytes. 

Before, AES was developed, and when the US government wanted to and was looking for a standard to protect its sensitive government information, a symmetric key algorithm was developed at IBM, named DES algorithm. DES did perform its function for a while but however, later on there were security concerns associated with DES. DES only has a 56 bit key, compared to the 256 bit in AES. As there was a prevalence of more hackers or attackers attacking the sensitive personal information of the users, the attacks against the DES increased. For instance, in 1997, it was the first time where DES was attacked, and the message that has been encrypted by DES was attacked and broken, by the Deschall project in an RSA security sponsored competition. Additionally, the Electronic frontier foundation (EFF) built a DES cracker that cracks the key in around two days. In 1999, EFFF and distributed.net, further collaborated to decrease the interval of two days to 24 hours. Hence, these events expressed that the DES encryption standard was not secure enough. As new encryption standards were researched, AES was approved to become the US federal standard in 2002, and after that it also became the standard that is recognized internationally (Ingram-Reid, Marvin, & Philips, 2020). DES takes plain text in blocks of 64 bits and it converts them to ciphertext using keys of 48 bits. As in AES, the same key is used for encryption and decryption, due to the symmetric key algorithm ("What is the DES algorithm"). To perform encryption and decryption of data, DES algorithm uses the Feistel structure, hence it uses some rounds to encrypt and decrypt data.

References

Rouse, M. (2020, April 17). What is AES Encryption and How Does it Work? Retrieved from https://searchsecurity.techtarget.com/definition/Advanced-Encryption-Standard

Advanced encryption standard. (n.d.). Retrieved from https://www.sciencedirect.com/topics/computer-science/advanced-encryption-standard