Block Ciphers and Stream Ciphers Block ciphers operate on blocks of data, typically of a fixed size called a block size . Each block is treated as a...
Block Ciphers and Stream Ciphers
Block ciphers operate on blocks of data, typically of a fixed size called a block size. Each block is treated as a single unit, and the encryption process is applied to each block independently. Once the blocks are processed, they are combined into a new, encrypted block.
Stream ciphers operate on a stream of data, which is a continuous flow of bits. Each bit in the stream is treated independently and encrypted using a key. The encryption process ensures that each bit is protected from unauthorized access.
Comparison:
Block ciphers are typically slower than stream ciphers, as they require each block to be processed separately.
Stream ciphers are more efficient, as they can encrypt a stream of data much faster than block ciphers.
Block ciphers are more secure than stream ciphers, as they are more resistant to attacks that can compromise individual blocks.
Examples:
Block ciphers: AES (Advanced Encryption Standard), RSA (Rivest-Shamir-Adleman)
Stream ciphers: AES (Advanced Encryption Standard), RC4, DES
Key Points:
Both block and stream ciphers use a key to encrypt and decrypt data.
Block ciphers operate on blocks of data, while stream ciphers operate on a stream of data.
Block ciphers are more secure than stream ciphers, but they are slower.
Stream ciphers are more efficient but are more susceptible to attacks