METHOD AND SYSTEM FOR GENERATING ELECTRONIC KEYS

FIELD OF THE INVENTION

The present invention relates to communication systems, and more particularly to a method and system for generating electronic keys.

BACKGROUND OF THE INVENTION

Electronic keys are well known and are typically used to provide access to secured devices or systems. For example, an electronic key may be required to execute functions or code on a device. Such functions may include, for example, accessing data in a memory device. To generate an electronic key for devices, each device is individually inserted into a socket, which is connected to a key generation system. Accordingly, after an electronic key is generated for one device, a new device can then be inserted into the socket. A problem with this conventional method is that generating electronic keys is time consuming. Accordingly, what is needed is an improved system and method for generating electronic keys. The present invention addresses such a need.

SUMMARY OF THE INVENTION

A method and system for generating electronic keys are disclosed. The method comprises providing a plurality of devices and generating an electronic key for each device of the plurality of devices, wherein the electronic keys are generated substantially simultaneously. According to the system and method disclosed herein, the electronic keys for all of the devices are generated in the same amount of time that is required to generate one electronic key for one device.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a block diagram of an electronic key generator in accordance with the present invention.

Figure 2 is a diagram of a portion of a molded strip, including lead frames, which can be used to implement some of the devices of Figure 1, in accordance with the present invention.

Figure 3 is a schematic diagram of a biasing circuit, which can be used to

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implement the enabling biasing circuit of Figure 1, in accordance with the present invention.

Figure 4 is a flow chart showing a method for generating electronic keys in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to communication systems, and more particularly to a method and system for generating electronic keys. The following description is presented to enable one of ordinary skill in the art to make and use the invention, and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein. A method and system in accordance with the present invention for generating electronic keys are disclosed. The method comprises providing a plurality of devices. While the devices are still in a molded strip and before the devices are singulated, electronic keys are generated for each device of the plurality of devices and the electronic keys are generated substantially simultaneously. To more particularly describe the features of the present invention, refer now to the following description in conjunction with the accompanying figures.

Figure 1 is a block diagram of an electronic key generator 100 in accordance with the present invention. The electronic key generator 100 includes a processor 102, a biasing circuit 104, and a strip socket 106, which connects to devices 108 that are in a molded strip. In operation, when the molded strip is inserted into the strip socket 104, the strip socket 104 makes electrical contact with each individual device 106. As described in further detail below, the electronic key generator 100 enables generation of electronic keys in the devices while the devices are still in the molded strip, prior to singulation. The electronic key generation for all of the devices 106 is performed substantially simultaneously. This provides substantial advantages over methods of electronic key generation where electronic keys are generated one by one for each device after each device has been singulated. Generating multiple electronic keys for multiple devices takes the same amount of time as generating one electronic key for a single device. For example, the amount of time required to generate electronic keys for 40

devices in a molded strip would take the same amount time as generating one electronic key for one singulated device.

Figure 2 is a diagram of a portion of a molded strip 200, including lead frames 202 and 204, which can be used to implement some of the devices 106 of Figure 1, in accordance with the present invention. The molded strip 200 also includes dambars 206, which are used to mold the device packages and functions as a physical stop, allowing mold compound to travel out a short distance but no farther. This extra mold compound forms a flash between the leads and in the area between the edge of the package and the dambar. After the devices are molded, the dambar 206 is removed (i.e., cut out) and the lead fingers of the lead frames 202 and 206 are cut and isolated from their respective tiebars. Figure 2 illustrates the lead frames 202 with the dambar 206 still intact and the lead frames 204 with the dambar removed. As described in further detail below, after the dambar 206 is removed, each device is electrically isolated from the other devices in the molded frame so that each device can be powered up, clocked, and can receive input signals.

Figure 3 is a schematic diagram of a biasing circuit 300, which can be used to ^• implement the biasing circuit 104 of Figure 1, in accordance with the present invention. In a specific embodiment, the biasing circuit 300 includes a bias power source 302, a secondary power source 304, a NAND gate 306 (e.g., a quad 2-input NAND gate), an inverter 308 (e.g., a hex inverter), a crystal oscillator 312 (e.g., a 33Mhz clock). The security chip 310 (e.g., an Atmel Trusted Platform Module (TPM) AT97SC32XX chip) represents a single instantiation of the devices 108 represented in Figure 1 and as shown in Figure 2 204.

In operation, the bias power source 302 supplies a voltage (e.g., 3.3V) via a switch 314 to the NAND gate 306. The secondary power source 304 supplies a voltage

(e.g., 3.3V) to the inverter 308, the crystal oscillator 312, and also to the electrically isolated security chips 310 in strip form. The crystal oscillator 312 provides a clock signal (e.g., 33Mhz) to the inverter 308 and to the security chip 310. In a specific implementation, the switch 314 is a momentary "ON" switch, which, when pressed, forces a low (0) input at the NAND gate 306 (e.g., at pin 11). Also, the inverter 308

(e.g., from pins 3, 9 , and 13) initialize its output (e.g., pins 8, 10, and 12 to high (1), low (0), high (1), respectively. Furthermore, in this specific implementation, firmware in the security chips 310 search for a high (1), high (1), low (0) combination on pins 1, 2, 3, respectively. Once the security chips 310 see a high (1), high (1), low (0) combination,

the firmware of each security chip 310 generates an electronic key for a given device.

Referring to both Figures 1 and 3 together, in operation, the biasing circuit biases the devices 108, and the devices 108 in turn generate an electronic key. The electronic key is self-generated by each device 108 using firmware within the silicon of each device 108. This insures that each device contains a unique electronic key.

The generation of an electronic key takes a certain amount of time (e.g., 3 seconds to 3 minutes) to generate. This can take a long time if there are a large number of devices, and the electronic keys are generated in a singulated fashion. The electronic key generator 100 saves a substantial amount of time, because the electronic key generator 100 generates electronic keys in parallel.

Figure 4 is a flow chart showing a method for generating electronic keys in accordance with the present invention. Referring to both Figures 1 and 4 together, the process begins in a step 402 when the plurality of devices is provided. In a preferred embodiment, the devices are provided in a molded strip. Next, in a step 404, the dambar is removed from the lead frame of the devices (Figure 2). This occurs after the devices have been molded. Once the dambar is removed, each device is electrically isolated from all other devices in the molded strip. Next, in a step 406, the molded strip of devices is inserted into the strip socket, which will allow the devices to be powered up, clocked, and able to receive input signals. Next, in a step 408, the biasing circuit biases the devices. Next, in a step 410, an electronic key for each device is generated, where the electronic keys are generated substantially simultaneously. Accordingly, the electronic keys are generated in parallel and before the devices are removed from a molded strip (i.e., before the devices are singulated).

According to the system and method disclosed herein, the present invention provides numerous benefits. For example, it generates keys in parallel. Generating multiple electronic keys for multiple devices takes the same amount of time as generating one electronic key for a single device.

A method and system in accordance with the present invention for generating electronic keys has been disclosed. The method comprises providing a plurality of devices. While the devices are still in a molded strip and before the devices are singulated, electronic keys are generated for each device of the plurality of devices and the electronic keys are generated substantially simultaneously.

The present invention has been described in accordance with the embodiments shown. One of ordinary skill in the art will readily recognize that there could be

variations to the embodiments, and that any variations would be within the spirit and scope of the present invention. For example, the present invention can be implemented using hardware, software, a computer readable medium containing program instructions, or a combination thereof. Software written according to the present invention is to be either stored in some form of computer-readable medium such as memory or CD-ROM, or is to be transmitted over a network, and is to be executed by a processor. Consequently, a computer-readable medium is intended to include a computer readable signal, which may be, for example, transmitted over a network. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.