Security specialist Data Encryption Systems (DES) has introduced a new version of its DES- lock+ tool that secures files and other data stored on PC hard drives through an encryption process that is transparent to users. The tool is primarily aimed at laptop users, but also runs on desktops.

DESlock+ 3.00, available now, comes in two versions. The business edition uses USB token devices to store and exchange encryption keys, while the personal edition uses a single key file held on the hard disk and is available for free download.

The software can be used to encrypt files or folders on the local hard drive, and a plug-in also allows users to send encrypted emails and attachments from Microsoft Outlook or Lotus Notes.

DES managing director David Tomlinson said the product is easy enough for users with minimal IT knowledge to encrypt files. "DESlock+ 3.00 does exactly what it says - it keeps your personal information safe," he added.

To secure files, users can either set up an encrypted folder that automatically encrypts files moved into it, or manually encrypt individual files via a DESlock+ menu option available by right-clicking with the mouse.

In the personal version, DESlock+ 3.00 uses a single encryption key stored in a key file on the hard disk. The business edition uses USB tokens that function like smartcards to create and store up to 64 encryption keys, which can be securely copied to users who staff need to communicate with, using the built-in RSA public-key algorithm.

"If you need to read a document I have created, I can send you my private key in a message, and that message will be encrypted using your public key so that only you can read it," Tomlinson said. This enables sharing of keys within a workgroup or with trusted partners, but key management software on the token stops the receiver from forwarding other users' keys to third parties, he added.

The tokens can also be used to securely store a small amount (2kB) of information, such as passwords for other systems.

DESlock+ 3.00 licences cost £25 + VAT per user while the hardware tokens cost £40 + VAT per token.