Which of the following statements are truei) In the CBC mode, the plaintext block is XORed with previous ciphertext block before encryptionii) The CTR mode does not require an Initialization Vectoriii) The last block in the CBC mode uses an Initialization Vectoriv) In CBC mode repetitions in plaintext do not show up in ciphertext

Advanced Encryption Algorithm and Block Cipher Operation topics are: AES algorithms, DES operation modes and triple DES methods.   The Advanced Encryption Standard (AES) is a symmetric block cipher algorithm that encrypts data using keys of 128, 192, and 256 bits. It is also known as the Rijndael algorithm.  AES has six modes of operation: ECB (Electronic Code Book) CBC (Cipher Block Chaining) CFB (Cipher FeedBack) OFB (Output FeedBack) CTR (Counter) GCM (Galois/Counter Mode)  AES is considered a secure encryption algorithm because of its large key sizes. The larger the key, the... Show more

Advanced Encryption Algorithm and Block Cipher Operation topics are: AES algorithms, DES operation modes and triple DES methods.
 

The Advanced Encryption Standard (AES) is a symmetric block cipher algorithm that encrypts data using keys of 128, 192, and 256 bits. It is also known as the Rijndael algorithm. 

AES has six modes of operation:
ECB (Electronic Code Book)
CBC (Cipher Block Chaining)
CFB (Cipher FeedBack)
OFB (Output FeedBack)
CTR (Counter)
GCM (Galois/Counter Mode) 

AES is considered a secure encryption algorithm because of its large key sizes. The larger the key, the harder it is to break the key through brute-force attacks. 
AES is used in software and hardware around the world to encrypt sensitive data. It's essential for government computer security, cybersecurity, and electronic data protection. 
A block cipher processes the data blocks of fixed size. Usually, the size of a message is larger than the block size. Hence, the long message is divided into a series of sequential message blocks, and the cipher operates on these blocks one at a time. 

Show less