The MD5 hashing algorithm produces a number (message digest) of what size regardless of how large the submitted source data.

Question

Options

• A32 bit
• B128 bit
• C512 bit
• DIts a function of the size of the input field

• A
  4% (1)
• B
  82% (23)
• C
  11% (3)
• D
  4% (1)

Explanation

MD5 always produces a 128-bit (16-byte) hash digest, no matter the input size - whether you hash a single character or a multi-gigabyte file, the output is always exactly 128 bits. This fixed-length output is a fundamental property of all cryptographic hash functions, which makes them useful for integrity checking and fingerprinting.

Why the distractors are wrong:

• A (32-bit): That's the size of common integers - far too small for a meaningful hash; MD5 uses 128 bits.
• C (512-bit): That's the block size MD5 processes internally, not the output - easy to confuse, but the digest itself is 128 bits.
• D (variable size): The whole point of a hash function is a fixed-length output regardless of input; variable output would break its core utility.

Memory tip: MD5 = "Makes Digests of 5 ...wait, 4 × 32 = 128." Think of MD5's output as four 32-bit chunks chained together - 4 × 32 = 128 bits. If you remember SHA-256 produces 256 bits, you can anchor MD5 at half that size.

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