Tungsten Network said on Tuesday it has been unaffected by the so-called Heartbleed bug.The Heartbleed bug, made public a week ago by Google and Codenomicon, has been used by hackers to steal information. A leading UK site for parents Mumsnet and the Canadian tax authority have both announced they have had data stolen by hackers, as a result of the Heartbleed security bug."This widespread problem emphasises the importance of security and compliance to our customers and market," Tungsten Network said "As such, we have decided to accelerate the termination of interoperability arrangements with networks that do not completely satisfy our compliance requirements."Shares fell 1.06% to 209.75p at 11:13 on Tuesday. RD