Businesses are preparing for the threat of a cyber attack by stocking up on digital currencies such as bitcoin to pay hackers' ransoms, new research reveals.

A third of firms in the UK are stockpiling in the event of such a cyber attack and the country's largest firms are willing to pay more than £50,000 for the return of their data or restoration of access.

Read more: Santander's using blockchain right now

But it's the biggest business who are doing the least stockpiling of digital currencies, with just 18 per cent of the 250 IT and security experts surveyed by Citrix saying their companies do this.

Smaller companies are more likely to keep a ready supply of cryptocurrency on hand.

More than a third of small firms (those with between 250 and 500 staff) are stashing digital cash in case of a ransomware attack, while of the mid-sized businesses with more than 500 but less than 1,000 staff surveyed, more than half said they were stockpiling.

Read more: Amazon and Goldman Sachs have backed this cyber security startup

While businesses may be preparing for attacks by buying up cryptocurrencies, they are less confident of being able to prevent one, however. Nearly half of firms area failing to back up data at least once a day, while a third of the experts said they were not getting enough advice from the government on how to avoid cyber attacks.