A start-up that dishes up an in-the-cloud security service says it also eliminates capital outlay for security gear and reduces ongoing support costs.

Zscaler imposes security policy as defined by customers and logs security activity for reporting and forensic analysis by customers. The service provides antivirus and antispyware, and can block the activity of bots, peer-to-peer networks, malicious content and phishing, the company said.

The service applies policies only to outbound Internet traffic on the fly, and can eliminate the need for multiple single-function devices at the edge of corporate networks, says the company's founder, Jay Chaudhry. He is also the founder of Cipher Trust (now part of Secure Computing), AirDefense (now part of Motorola) and SecureIT (now part of VeriSign).

Customers proxy outbound Internet traffic to the nearest Zscaler gateway, where it is scanned and cleaned, Chaudhry says.

To engage the service, customers point traffic that goes through edge devices such as firewalls and routers toward Zscaler gateways. For remote access users, they change browser settings to direct traffic at the gateways.

Currently these gateways are located in Atlanta, Chicago, New York and Washington, DC, with a central storage facility in San Jose, California, and a mirror site in Freemont.

Other gateways are planned for elsewhere in the United States and Europe, Chaudhry says.

Zscaler relies on two other unnamed vendors for its signature-based antivirus software and its URL database, but the rest of its technology is home-grown.

This includes a high-performance proxy engine, a software architecture that allows a single instance of security applications that can handle multiple users' traffic, compression technology that reduces logs by 50-fold and a global network.

Policies set by customers are enforced by equipment in Zscaler's data centre no matter which gateway the traffic enters. Services include straight-up security functions plus management of Internet traffic to control access to social networking sites, streaming content and web mail, for example.

The service can help with regulatory compliance by blocking, for instance, attachments in instant messages or uploading of files. Logs allow for audits and investigation of security incidents.

Zscaler service is available now and is priced based on the number of users and the number of security functions the service performs. That ranges from $1 (50 pence) to $5 per user per month.