Into The Grey Zone: China and Russia cyber threats can't be lumped together like 'Chas & Dave'

• China and Russia pose the biggest state-backed cyber threat to the UK but you cannot lump them together like "Chas & Dave", the musical duo, a former top cyber official has said. Instead, the two countries present very different challenges, according to Ciaran Martin, who was the head of GCHQ's National Cyber Security Centre until last August.