Storage giant SanDisk has come up with a new half-way house for consumers who want to use encryption on portable USB without getting too techie.

All of the company’s USB sticks starting with its new Ultra USB and Cruzer Edge models will now offer users the ability to create a 128-bit encrypted vault within an otherwise unencrypted drive.

Set up and accessed using SanDisk’s SecureAccess software, the vault idea is supposed to overcome a disadvantage of using full-drive encryption, namely that files are hard to share.

Until now the choice has been between business-class USB drives with encryption and consumer drives with no security at all. The vault is really aimed at consumers who want the best of both worlds, encrypting some files while sharing others.

SanDisk claims to have made using the encrypted partition as simple as possible, including the ability to drag and drop files between the encrypted and non-encrypted parts of the drive.

The company will also offer a complimentary 2GB online backup service through a partnership with Dmailer.

One issue with encrypted vaults that can be set up using software (for instance the open source program Truecrypt) is that the vault size is fixed at the time of creation, which can be inconvenient when it eventually fills up. Users find themselves trying to remember which of several vaults a particular file might be inside.

SanDisk appears to come up with a way around that issue in that the encrypted vault adjusts its size automatically as the vault grows.

The SanDisk Ultra USB Flash Drive costs from £18.99 (8GB) to £60.99 32GB), with the SanDisk Cruzer Edge USB Flash Drive costing £10.99 (4GB) to £25.99 (16GB).