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SY0-301 · Question #445

Which of the following encrypts data a single bit at a time?

The correct answer is A. Stream cipher. Stream ciphers encrypt data one bit or one byte at a time by XOR-ing a continuous keystream with the plaintext, in contrast to block ciphers which operate on fixed-size chunks of data.

General security concepts

Question

Which of the following encrypts data a single bit at a time?

Options

  • AStream cipher
  • BSteganography
  • C3DES
  • DHashing

How the community answered

(30 responses)
  • A
    87% (26)
  • B
    3% (1)
  • C
    7% (2)
  • D
    3% (1)

Why each option

Stream ciphers encrypt data one bit or one byte at a time by XOR-ing a continuous keystream with the plaintext, in contrast to block ciphers which operate on fixed-size chunks of data.

AStream cipherCorrect

A stream cipher generates a pseudorandom keystream and applies it to plaintext one bit at a time using an XOR operation, making it well suited for real-time or continuous data encryption where block-size alignment is impractical.

BSteganography

Steganography conceals the existence of data within another file and is not a cipher or encryption process that operates on individual bits.

C3DES

3DES is a symmetric block cipher that encrypts data in 64-bit blocks by applying DES three times, not bit-by-bit.

DHashing

Hashing is a one-way function that produces a fixed-length digest and is not an encryption mechanism that processes data bit by bit.

Concept tested: Stream cipher vs block cipher operation

Source: https://csrc.nist.gov/glossary/term/stream_cipher

Topics

#stream cipher#encryption#cryptography#bit-level encryption

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