The third element is the frequent use of a dictionary to eliminate misunderstandings.

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Or they use a "dictionary attack, " an elaborate guessing game in which thousands of address combinations are tested for validity.

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"To be told in my own country I can't use a word in the English dictionary - it's nonsense, " said Mr McColghan.

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But because they use cryptographic hashes to obscure those words, the computing power to run a dictionary attack has long been unavailable to most users.

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