What type of cryptographic technique transposes the order of letters or words to obscure meaning?

The correct answer is transposition. This cryptographic technique alters the order of letters or words rather than changing the letters themselves. By rearranging the characters, transposition ciphers effectively disguise the original message while maintaining the exact characters used, allowing for the reconstruction of the message when the correct order is known.

For instance, with a simple transposition cipher, the phrase "HELLO WORLD" could be transformed into "OLLEH DLROW" simply by reversing the order of the letters within the entire message. This method relies on the secret arrangement of the letters, which can create different meanings based on how the characters are ordered. The key advantage of transposition ciphers is that they maintain the same set of characters, making them less prone to frequency analysis attacks compared to certain types of substitution ciphers.

In contrast, substitution involves replacing each letter with another letter or symbol, which modifies the characters directly and can make the original text unrecognizable based on character frequency. Polyalphabetic ciphers further complicate substitution by using multiple forms of substitution based on a key, enhancing security but still differing fundamentally from transposition in how the data is obscured. A ciphertext-only attack, while a tactic used in cryptanalysis, does not pertain