Cyber security start-ups have become the latest fascination for Silicon Valley investors, who have flooded the sector with venture capital investment as they seek to back the latest technology to combat criminals online.

Early-stage funding for the sector soared by almost 60 per cent last year to $244m worldwide, according to data from research group PrivCo. The number of deals rose even faster, up more than 100 per cent year-on-year to more than one a week. The figures imply multibillion-dollar valuations in total for these young companies, which often only have a small number of employees.

The investment boom in cyber security companies comes as cyber crime is on the rise and recent high-profile attacks, such as the data breach at US retailer Target and the theft of customer details at Adobe, the software company, have highlighted the extent of the threat.