With the advent of personal computers in the mid to late 70's, the use of computers for home and office has dramatically increased. As a result of the rapid development of technology, the size of the computer has also been greatly reduced. A variety of advanced notebook computers as well as hand-held devices have been developed. The application of computers greatly improves working efficiency, and shortens the distance between people. Regular hand-held devices are designed for particular purposes. However, due to certain limitations in technology, these hand-held devices typically cannot replace personal computers.
Therefore, these hand-held devices are commonly used in certain conditions to store and process certain types of data. As an example, a handheld device may be used in a warehouse to track movement of goods in, out and within the warehouse. For long-term preservation of the information being stored in a hand-held device or for a complicated analysis of the information, communication technology may be employed to transmit the information from the hand-held device to a personal computer, server computer, or other networked machine. At the present time, a variety of communication networks have been used for the transmission of information from a distance. It is important to efficiently utilize obtained information, and to well protect it.
Conventionally, a user may protect one's private information in a computer system by setting a code in it, or encrypting one's private information by means of the application of an encryption procedure. If a user owns a hand-held device and a personal computer, the user may need to set a code in the hand-held device and the personal computer separately, or to use an encryption procedure in encrypting the information in the hand-held device and the information in the personal computer. This method is complicated, and its effect is still not guaranteed. The code set in a computer system can be easily broken. To a computer hacker, it may be easy to break a password set in a computer system by means of employing code-breaking procedures or tracing the password.
Other problems with storing data on mobile devices are due to data corruption and theft. Typically a single user interacts with the mobile device so there is no multi-user operating system which requires some type of security measures or a password. Therefore data is extremely accessible and vulnerable. Also conventional forms of data encryption such as symmetric encryption are found to be too CPU intensive for a hand-held device.
Data encryption for PDA or handheld devices (personal devices) is presently limited by a variety of factors. Resources such as processors and memory may be limited on a personal device. As a result, encryption can be either time-consuming (reducing efficiency) or ineffective. Similarly, encryption facilities tend to be limited—for example operating systems for personal devices typically have limited or no encryption facilities. Operating systems may provide a logon password used to allow the device to power-on or for initial operation of the device, but may not provide the ability for multiple users to access some data universally and reserve other data as segregated, encrypted data.
Therefore the conventional data encryption and storage techniques within a mobile computer system have severe limitations and a more appropriate solution is sought that offers both high security and efficient encoding and decoding of data. Preferably, capabilities beyond those outlined above would be provided, allowing for access to some data by all users and private access to data by specified users. Moreover, such capabilities would preferably be offered in a manner allowing for integration with present software (such as operating systems) and future software used on personal devices. Additionally, allowing for retrieval of information in unusual circumstances where a device is stolen or a user is unable or unwilling to provide access to the device normally may be useful.