Passive protection against security compromise or possible insecurity when information/communications devices are lost

The information on devices like notebook computers and PDAs is often worth many times the value of the devices themselves. When a notebook computer or PDA is lost or stolen, it is desirable to deny access to that information. Similarly, portable communications devices often provide gateways into secure information networks. When lost or stolen, the entire network becomes vulnerable. Crypto ignition keys (CIK) are often used to render such devices useless to unauthorized users, but as devices become smaller and more portable the likelihood of their becoming lost or stolen with the CIK installed increases. In this case the information is not protected. A novel security technology creates an envelope around the user with in which secure operations can occur. When the information or communications device is outside of that envelope, information is automatically protected with no action needed on the part of the authorized user. When the security envelope is broken and the unit protected is rendered harmless, the user can easily reestablish the security envelope when he regains control of the protected unit.