Cash still has important roles to play in modern society, according to Antti Heinonen, former head of banknotes at the European Central Bank.

Cash is a part of the "national infrastructure", and is important for its reliability in times of crisis, Heinonen said during an interview on the sidelines of Central Banking's seminar series in Windsor, UK.

"Cash has also been evolving recently... we have state-of-the-art security features, there is a paradigm change in the durability of banknotes and