In messaging security controls - such as malware and spam detection/exclusion for e-mail and instant messaging - cloud-based services account for 20% of of the sector's revenue in 2008, said Gartner.
By 2013, cloud-based services in messaging security controls will account for 60% of revenue, Gartner said.
Cloud computing will enable security controls and functions to be delivered in new ways and by new types of service providers.
It will also enable enterprises to use security technologies and techniques that are not otherwise cost-effective, said the analyst.
Gartner defines cloud computing as a style of computing where massively scalable IT-related capabilities are provided "as a service" using internet technologies to multiple external customers.