Ransomware highlights the challenges and subtleties of cybersecurity

FOR THE past month Ireland’s health-care system has been in disarray. On May 14th the Health Service Executive (HSE), the state-funded health-care provider, was hit by a “ransomware” attack which led it to shut down most of its computer systems. The attackers threatened to release stolen data, including confidential patient records, unless the HSE stumped up $20m (€16.5m). It declined to do so. Its staff were reintroduced to pen and paper, its procedures delayed, its patients inconvenienced. By June 14th services had still not returned to normal.