New opportunities for online advertisers arise with the possibility of one-to-one Web applications. Software agents for example promise to "register, recognize and manage end-user profiles; create personalized communities on-line; deliver personalized content to end-users and serve highly targeted advertisements". The probably ultimate tool for advertisers. Although not yet widely used, companies like
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The Enigma Encryption Machine was famous for its insecurities as for the security that it gave to German ciphers. It was broken, first by the Poles in the 1930s, then by the British in World War II.