FUNDAMENTALS OF COMPUTER

Detailed explanation-1: -Stream algorithms are faster and more efficient than block ciphers because they’re encrypting only one bit of data at a time into individual symbols rather than entire blocks. So, they’re better suited for devices that have fewer resources.

Detailed explanation-2: -Block ciphers transform plaintext 1 block (64/128/256 bits) at a time, while stream ciphers convert plaintext to ciphertext 1 byte at a time. This makes block ciphers slower since an entire block has to be accumulated before the data is encrypted/decrypted.

Detailed explanation-3: -Since a block cipher converts blocks at once, it converts more significant bits than a stream cipher, which can convert 64 bits or more. However, in stream cipher, only 8 bits can be transformed simultaneously. It is difficult to reverse encrypted text.

Detailed explanation-4: -An important distinction in symmetric cryptographic algorithms is between stream and block ciphers. Stream ciphers convert one symbol of plaintext directly into a symbol of ciphertext. Block ciphers encrypt a group of plaintext symbols as one block. Simple substitution is an example of a stream cipher.

Detailed explanation-5: -arcfour is the fastest cipher, and aes128-cbc is faster than the default aes128-ctr. Note that blowfish-cbc is not particularly fast. ssh is faster than netcat using either the aes128-cbc or arcfour ciphers.