Cybersecurity is a sector that is attracting serious investment these days, particularly in the wake of 2013’s "Year of the Breach" and its more potent sequel the "Year of the Mega-Breach".

With that in mind, it is fitting that the home of Alan Turing, Bletchley Farm and GCHQ is producing its fair share of companies dedicated to combating the surge in cyberattacks.

Based on the Cybersecurity 500, a list of the world’s hottest cybersecurity companies, we have pulled out the best that Britain has to offer in the industry. Here’s what you should know:

1. BT

Field: Network Security
Headquarters: London

Though mostly a telecoms company, BT has also invested in a cybersecurity portfolio, chiefly in the form of a managed security service based around the network.

The promise from BT is that this gives you oversight of your assets, helping you to identify potential threats and react to them. The company also offers a penetration testing service, defence against fraud and identity theft through authentication, and secure file transfer tools.

All that defends your assets, but for those seeking to keep the network running BT Assure also provides continuity planning, protecting the firm against denial-of-service attacks from fiends like Lizard Squad, who allegedly shut down gaming networks at the end of last year.

2. Clearswift

Field: Data Loss Prevention
Headquarters: Theale, Berkshire

In the Information Age the currency of a company’s data is rising, both in terms of intellectual property and the information businesses must hold on their customers and staff.

As such defending data has become a priority for many companies, with firms like Clearswift offering tools to protect against information leakage. Its Adaptive Data Loss Prevention tool aims to do this by tracking data without getting in the way of the work that staff need to do.

Other products offered by the firm also keep to the same theme, with email and web gateways looking to secure information sent through electronic messaging or collaboration tools such as Dropbox.

3. Sophos

Field: Antivirus and Malware Protection
Headquarters: Abingdon, Oxfordshire

Sophos is an old hand in the cybersecurity game, having first emerged some 30 years ago in the antivirus and encryption markets.

Antivirus remains one of the company’s core fields, but the company has also branched out across networks, servers and mobile devices. On the networks side its products include next generation firewalls, web and email gateways, and secure Wi-Fi.

Elsewhere Sophos boasts a range of endpoint solutions protecting everything from mobiles to the cloud, with the range rounded off by an email protection service.

4. Silobreaker

Field: Cyber-analytics and Risk Intelligence
Headquarters: London

Analytics is one of the key fields in which cybersecurity vendors are innovating in the hope that they can make up for a severe lack of talent in the sector.

Silobreaker is among the key players in security data, having been formed in 2005. Like many of its rivals one of its main tasks is filtering down the plethora of data around security, giving IT departments manageable amounts of alerts to work with.

To do this the company’s software integrates data from as many sources as possible into a series of dashboards, with the product being available both an on-premise and as a managed service.

5. Swivel Secure

Field: Authentication
Headquarters: Wetherby, West Yorkshire

Swivel’s speciality comes in the form of an authentication platform that provides security across cloud, web, virtual private network (VPN) and desktop applications.

The firm’s strategy revolves around the use of two-factor authentication, which requires users to have a physical token such as a smartphone in order to log into various services. Such security is widely regarded as superior to a mere password.

Whilst the product is fairly simple its advantage is that it can be deployed across many situations and used by a range of different devices, including smartphones, tablets and desktops.