Unit 3: task option 2


I have 2  interesting examples of codes can support a lesson about encoding and decoding messages.(2 digital ):


TripleDES (sometimes written as 3DES or TDES) is a newer, more secure version of DES. When DES was cracked in less than 23 hours, people realized the problem, so this is why TripleDES was born. TripleDES speeds up the encryption process by running DES three times.

The data is encrypted, decrypted, and then encrypted again, giving an effective key length of 168 bits. It is long enough for the most sensitive data. However, although TripleDES is longer than standard DES, it also has its flaws.

TripleDES has three locking options:

Key Option 1: All three keys are independent. This method provides the strongest key strength: 168 bits.

Option Key 2: Key 1 and Key 2 are independent, while Key 3 is the same as Key 1. This method provides an effective key strength of 112 bits (2 × 56 = 112).

Key Option 3: All three keys are the same. This method provides a 56-bit key.

Option Key 1 is the strongest. The Key 2 option isn’t as strong, but still offers more than twice as much protection as DES encryption. TripleDES is a block cipher, meaning that data is encrypted according to a fixed block size. However, TripleDES block size is small at 64 bits, making it somewhat susceptible to certain attacks (like block collisions).


Advanced Encryption Standard (Advanced Encryption Standard – AES)

Advanced Encryption Standard (AES) is currently the encryption standard used by the US Government. It is based on the Rijndael algorithm developed by two Belgian cryptographers, Joan Daemen and Vincent Rijmen. Belgian cryptographers have submitted their algorithm to the National Institute of Standards and Technology (NIST), competing with 14 other ciphers to be the next cipher. after DES. Rijndael “won” and was selected as the proposed AES algorithm in October 2000.

AES is a symmetric key algorithm and uses a symmetric block cipher. It consists of three main sizes: 128, 192 or 256 bits. Furthermore, there are different encryption rounds for each key size. A round is the process of converting raw text into ciphertext. For 128-bit, there are 10 rounds; 192-bit has 12 rounds, and 256-bit has 14 rounds.


There are theoretical attacks against the AES algorithm, but they all require a certain amount of time and specific data to be stored, so it’s not feasible at the moment. For example, an attack on AES encryption requires 38 trillion data, more than all the data stored on all computers worldwide in 2016. Estimate the time it takes to generate the ton. AES-128 key brute-force is billions of years.

+ There are no comments

Add yours