The cloud-based security services market will be worth $2.1 billion in 2013, rising to $3.1 billion in 2015 as growth in cloud-based security remains strong, yet Gartner forecasts revenue opportunities will vary.

"The cloud-based security market remains a viable one, offering providers many opportunities for expansion," says Ruggero Contu, research director, Gartner.

"Encryption will be a new area of growth, but it remains a complex activity.

"The strongest interest will be in encryption products from cloud security brokers, which are relatively easy to deploy and have options for on-premises encryption management."

Gartner predicts that the top three most sought-after cloud services moving forward will remain email security, web security services and identity and access management (IAM).

However, in 2013 and 2014, the highest growth is forecast to occur in cloud-based tokenisation and encryption, security information and event management (SIEM), vulnerability assessment and web application firewalls.

"Areas such as SIEM and IAM offer the biggest growth potential, although for SIEM this will be from a small base," adds Kelly Kavanagh, principal research analyst, Gartner.

"The benefits cloud security offers — particularly encryption — are making it an increasingly popular choice.

"However, trust concerns and regional variations mean that providers will have to assess each market opportunity carefully before deciding which to focus on."

Kavanagh claims that overall, adoption of software as a service (SaaS) applications and other cloud-based services encourages organisations to adopt cloud-based security controls, delivered either as stand-alone features or as part of an integrated SaaS package.

Managed security services (MSS) are also driving adoption of cloud-based security services among enterprises. MSS delivery models are in turn being affected by demand for cloud-based security services, which is enabling security providers to become de facto MSS players.

"The benefits of deploying cloud-based security services are clear," Kavanagh adds.

"Aside from the broad area of IAM, specific controls, such as encryption, are becoming vital to the adoption of cloud computing.

"They are further helping to generate interest in this particular form of security service delivery."

Cloud-based security acceptance

Gartner expects acceptance of, and reliance on, cloud-based security-as-a-service offerings to increase, based on organisations gaining more experience with SaaS and more consumer-grade technology being made available to corporate systems as a result of trends, such as bring your own device (BYOD).

Cloud-based security services will grow faster than the market for remotely monitored customer premises equipment (CPE) MSS through 2012, but starting from a smaller base.

In the next 24 months, new security-as-a-service-based offerings that address specific security controls for cloud-based IT resources will be available from larger IT and network service providers, aimed initially at small or midsize businesses (SMBs).

Gartner predicts that smaller, pure-play managed security service providers (MSSPs) will be most affected by the introduction of these services, and expects them to consolidate.

Within the IAM space, interest in cloud-based security has been driven mostly by SMBs' needs to extend their basic IAM functions and serve employees who are accessing SaaS and some internal web-architected applications.

An increasing number of organisations seem to be adopting cloud-based IAM services to replace IAM on-premises tools. Larger businesses are often looking to use IAM as a mixture of legacy- and web-architected cloud and on-premises.

"Although organisations' interest in encryption is expected to grow, service providers' relative lack of interest in cloud-based encryption means it has remained a complex activity, requiring organisations to initiate complex, build-your-own deployments," Contu says.

"The strongest interest is in encryption products from cloud security brokers, thanks to their relative ease of deployment and their options for on-premises encryption management.

"Nevertheless, Gartner expects cloud hosting providers and IaaS providers to show an increased interest in cloud-based encryption capabilities."