Tom Berson, a California cryptographer hired by Skype in 2005 to evaluate its security, says he met the programmers, who told him they grew up when Estonia was part of the Soviet Union and had the perils of "wiretapping in mind" when creating Skype.

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The alliance has already welcomed former Soviet republics such as Latvia, Lithuania and Estonia.

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In Soviet times, any foreign dignitary or journalist arriving in Estonia would be whisked straight from the airport to Hotel Viru.

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Mr Bush has become the first American president to visit Lithuania, which along with its Baltic neighbours Latvia and Estonia won independence in 1991 after half a century of Soviet occupation.

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In pubs in cobbled Tallinn, Estonia's perky capital, whose Hanseatic flavour now far out-smells its Soviet one, Mr Ilves, aged 44, clad in billy-cap and leather jacket, has an easy rapport with Estonia's go-ahead young.

ECONOMIST: Toomas Ilves, Estonia��s American-European