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WIRELESS SECURE DEVICE
This application claims priority under 35 U.S.C. § 119(e) 5 to U.S. Provisional Application Ser. No. 60/258,843 filed Dec. 27, 2000, by Samer Abdo, Rolf Ambuehl, and Olivier Bodenmann, and U.S. Provisional Application Ser. No. 60/300,563 filed on Jun. 22, 2001, by Samer Abdo, Rolf Ambuehl, and Olivier Bodenmann, which are assigned to 10 the same assignee as the present invention and are incorporated, in their entirety, herein by reference.
1. Field of Invention
The present invention relates to a method and a system for wireless communication between a peripheral device and a host computer system (host system), and more particularly relates to a method and a system for establishing a secure 20 connection between one or more wireless peripheral device and one or more host systems.
2. Background of the Invention
Numerous methods for connection of peripherals to host systems, e.g., personal computers and workstations are 25 known in the art. For example, corded peripherals, or peripherals connected to host systems using a cable or corded connection through either an industry standard serial (RS-232) or parallel port, are known in the art. As known to one of skill in the art, RS-232 stands for "recommended 30 standard-232C," a standard interface approved by the Electronic Industries Alliance for connecting serial devices. This method, although effective in many circumstances, suffers from certain limitations. One limitation is the restriction on the user's freedom of movement. A second limitation is that 35 host systems have only a limited number of available ports, and thus can only support a limited number of peripheral devices. Another limitation is the clutter and complexity that having a large number of wires or cables brings. An increasing number of peripherals are being connected to host 40 systems bringing a proportional increase in clutter and confusion from the mass of wiring required to connect multiple corded peripherals to a host system. Thus, there has been a need for cordless peripherals.
Cordless peripherals are also known in the art. A common 45 approach uses infrared ("IR") transmissions to connect a peripheral device with a host system. Remote control devices used with modem home electronics such as a television, videocassette recorder or stereo is an example of cordless communication between a peripheral and a host 50 system using infrared signals. While solving some of the limitations of corded peripherals, cordless transmission systems using infrared signals have the limitation of the transmitting peripheral must be aligned with the host system, therefore, obstacles in the line of sight path between the 55 peripheral and the host can hinder a transmission. This limitation makes infrared-based communications unworkable when it is difficult to keep a given peripheral in alignment with the host system.
More recently, other wireless devices have been intro- 60 duced. For example, cordless peripheral devices, which connect with host systems through radio frequency ("RF") transmission systems, are known in the art. RF technology allows cordless communications between a peripheral and a host system without concern for alignment or obstacles, 65 which could impede infrared communications. While both IR and RF devices have been effective in providing cordless
communication between a single peripheral and an associated host, these devices, which generally use a conventional system of identifiers (e.g., Short_ID) to try to ensure data privacy, are vulnerable to interference with configurations in which multiple peripherals wirelessly connect to single or multiple host systems. Such interference can simply be coincidental, a host system might erroneously recognize an unrelated peripheral as an authentic peripheral, or may be intentional in the form of malicious eavesdropping.
Thus, there is a need for a communication device, which would permit elimination of cabled or wired connections between a peripheral and a host system, while providing a secure connection that allows one or more cordless, or wireless peripherals to securely communicate with one or more hosts systems that associated with that wireless peripherals communicate with that host system.
SUMMARY OF THE INVENTION
The present invention overcomes the limitations of the prior art by providing a method for securely connecting one or more wireless peripheral devices and one or more host systems (e.g., personal computers or workstations), the secure connection being highly resistant to coincidental as well as potentially intentional or malicious interference. The secure connection includes an encryption/decryption process to protect communications between the wireless peripheral device and the host system.
The system provides the option between establishing a normal connection or data link or a secure data link between a wireless device and a host system. When operating in a secure connection mode, it is highly improbable that a wireless device can be connected to and communicate with a host system other than the one to which it is intended to be connected. In one embodiment, the process for providing a secured data link includes providing a wireless peripheral device with an encryption key, generated by a host system, without directly transmitting the encryption key to the wireless peripheral device, and validating that an encryption/decryption process of a secure link is operational, again without having to transmit an encryption key directly between the wireless device and the host system. In one embodiment, the wireless devices and a receiver unit coupled to the host system, respectively, internally generate sensitive information such as a device identifier and the encryption key. This internal generation of sensitive information makes it difficult for an eavesdropper to force a given value to the identifier or the encryption key.
In another embodiment, the present invention also provides a process for guiding a user through a secured link process, as well as for monitoring the status of the secured link, informing a user of the status of the data link (e.g., normal link (mode) or secured link (mode)), and for warning the user if the security mode is switched off without permission being granted.
The features and advantages described in the specification are not all inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
The Figures depict embodiments of objects and features of the present invention(s) and are for illustration purposes only. The Figures are more fully disclosed in the following 5 detailed description, reference being had to the accompanying drawings, in which:
FIG. 1 is an illustration of a wireless peripheral device, such as a keyboard, and a host system 101, such as a computer. 10
FIG. 2A is an illustration of a general frame structure of a transmission according to the protocol of the present invention.
FIG. 2B is an illustration of the contents of the FRAMECONTENT field available in accordance with the protocol 15 of the present invention.
FIG. 3A is an illustration of a standard keyboard data format.
FIG. 3B is an illustration of an encrypted keyboard data format. 20
FIG. 4 is an illustration of a process of establishing a secure connection in accordance with the present invention.
FIG. 5 is a flow diagram of one embodiment of an encryption process in accordance with the present invention.
FIG. 6 is a flow diagram of one embodiment of a 25 decryption process in accordance with the present invention.
DETAILED DESCRIPTION OF THE
Reference will now be made in detail to several embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings. It is noted that wherever practicable similar or like reference numbers may be used in the figures and may indicate similar or like 35 functionality. One of skill in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods disclosed herein may be employed without departing from the principles of the invention(s) disclosed herein. 40
It is noted that, for ease of discussion, the following descriptions of the present invention are made with reference to connecting a wireless keyboard 115 to a host system 101, which merely represents one embodiment of the present invention. Those of skill in the art will recognize that 45 the principles described are also applicable to connecting other wireless peripheral devices, such as wireless mice, trackballs, gaming devices, joysticks, and cameras to a host system 101.
The present invention includes a system and method for establishing one or more simultaneous secure connections or data links between one or more wireless peripheral devices and one or more host systems 101. 55
Referring first to FIG. 1, a wireless peripheral device, for example, a wireless keyboard 115, communicates wirelessly with a host system 101, typically a handheld computer, a personal computer, or a workstation. In addition to a keyboard, other suitable peripheral devices 115 may include, for 60 example, electronic mice, trackballs, touchpads, joysticks, game controllers, game pads, and digitized tablets and pointing devices used in software presentations.
In one embodiment, the wireless keyboard 115 includes a memory 125, which can be volatile (e.g., random access 65 memory) or non-volatile, for example, an Electrically Erasable Programmable Read-Only Memory or a flash chip, a
processor 119 including an encryption module 121 and a signal generator 123, and a transmitter 117. The memory 125, and the processor 119 including an encryption module 121 and a signal generator 123, and a transmitter 117 are further described below.
The host system 101 includes a receiver or host adapter 111, a host computer 102, and a display unit 103, for example a screen such as a computer monitor. The receiver 111 is coupled to the host computer 102, and the host computer 102 is coupled to the display unit 103. In one embodiment, the components of the host system 101 are connected via USB links. In addition, the receiver 111 includes a non-volatile memory 113, and a processor 105 including a signal generator 109 and a decryption module 107. The host computer 101, the receiver 111, which includes memory 113, the processor 105 including the signal generator 109 and the decryption module 107, and the display unit 103 are further described below. Additional embodiments of a wireless peripheral device/transmission unit, for example, a wireless keyboard 115 and receiver/host adapter 111 is described in U.S. Pat. No. 5,854,621, entitled WIRELESS MOUSE and assigned to the assignee of the present invention, the relevant portions of which are incorporated herein by reference.
In an additional embodiment, the keyboard 115 includes a connection button 127, with which to initiate a connection with the host system 101. Furthermore, while FIG. 1 describes one embodiment of the present invention in which the keyboard 115 communicates uni-directionally to the host system 101, in another embodiment, the present invention supports bi-directional communications between a keyboard 115 and a host system 101 and each device may include both a transmitter and a receiver 111.
A method of the present invention is equally applicable to infrared (IR) or radio frequency (RF) operations. In one embodiment, in addition to JR operations, the Infrared Data Association (IRDA) standard operations may be used to implement the system. If an JR implementation is applied, the carrier wavelength will typically be within the range of 850-950 nm, and may be within the IRDA range of 850-900 nm. The carrier frequency may vary widely, but will typically fall within the range of 30-56 kHz. The LED-on time typically varies between 3 us to 50% of the carrier period. A shorter on time provides better power savings, while a longer on time provides better range, with the exact on time being determined in accordance with a specific implementation. In some instances, adaptive criteria may be used to determine on time. Any suitable modulation technique is acceptable, such as FSK (Frequency Shift Keying), PSK (Phase Shift Keying), Q-PSK (quadrature phase shift keying) or others, although ASK (Amplitude Shift Keying) is presently preferred because components implementing this technique are readily available. A variety of data encoding algorithms may be used. Certain embodiments of data encoding algorithms that the system may utilize are disclosed and described in U.S. Pat. No. 6,078,789, entitled WIRELESS PERIPHERAL INTERFACE, which is assigned to the assignee of the present invention, the relevant portions of which are incorporated herein by reference. In one embodiment, Miller "Delay Modulation" encoding is preferred, at a rate on the order of 2400 bps and a no-emission time of 2.5 bits minimum at the receiver 111 side. Any suitable directivity may be used, with such directivity controlled in a manner known in the art. In the event the system 101 utilizes a RF link between the keyboard 115 and the host system 101, the system 101 can utilize various carrier frequencies. For example, carriers on the order of 233