Design and Internal Exploration of Embedded Multiple Identification Intelligent Access Control System

With the development of social economy, the demand for safer and more convenient identity authentication and access control has become increasingly high for electronic devices and security agencies. Traditional mechanical keys, passwords and passwords, and smart cards have hidden risks of loss, forgetting, copying, and theft. The application of biometrics technology provides a good solution to the deficiencies of the above methods. Applying automatic fingerprint recognition technology to various systems requiring authentication or embedding into existing security management systems will greatly increase the security of the system. This system is an embedded multiple-identification access control system constructed by combining multiple identification technologies such as radio frequency identification technology (electronic tag) and fingerprint automatic identification technology, especially for the temporary authorization defects existing in the conventional security system itself. The security of the electronic security system composed of digital watermarking technology in the document is more effective and can be applied to security, confidentiality and other departments. Its design idea can also provide reference for the design of similar products.

2 system design scheme This system will change the existing "IC card mode" to "electronic tag mode" and add a "fingerprint identification level" to achieve uniqueness in identity recognition. The use of non-cardholders will be You will encounter an insurmountable obstacle in fingerprint recognition. Through the "one person, one card, one library" model, the authenticity and objectivity of data are effectively guaranteed. After the recognition, the elevator door opening system or other access control system will be activated. At the same time, the gravity sensing system will be activated to verify whether it is overweight (to prevent the cardholder being hijacked). If it is overweight, start the camera system video and start the alarm system.

The authorization authorization system is designed because the cardholder information is input into the background in advance and there are obvious defects in the modification of the temporary permission. In this system, we introduced the application technology of digital watermarks on electronic documents so that lower levels can directly apply for temporary permission modification through the local area network. After the two parties reach an agreement, the digital watermarks are affixed to the third party on the back-end and they are confirmed as being signed by each other. After the chapter made amendments to the applicant's card permissions.

2.1 Microcontroller Microcontroller Using 89s52 chip and high-performance CMOS 8-bit microcontroller, the chip contains 8k bytes of rewriteable read-only program memory (PEROM) and 256 bytes of random access data memory (RAM). The compatible standard MCS-51 instruction system produced by ATMEL's high-density, non-volatile memory technology has a built-in general-purpose 8-bit CPU and Flash memory unit. The AT89C51 is a low-power high-performance microcontroller, especially Flash memory that is repeatedly erased can effectively reduce development costs.

2.2 Radio Frequency Identification Technology This system uses a 16-bit card reader provided by Taiwan Tianyu Micro Electromechanical Co., Ltd., which is a TN951P311 data transmission baud rate of 3K. It is used in the elevator authority and access control screening module respectively. After the system is processed by the microcontroller, it is connected to the PC via the serial port. Using a contactless smart card (also known as a radio frequency card), it can easily integrate RFID technology and IC card technology, and package integrated electronic device (ASIC) and antenna with microprocessor and large-capacity memory in plastic. The function in the substrate. Among them, the antenna is only a few sets of winding coils, and is suitable for packaging in a card conforming to the international standard ISO7816; the card shape is basically the same as an ordinary credit card, and information is stored and processed by an application-specific integrated circuit (ASIC) in the card. The ASIC consists of a high-speed radio frequency interface, a control unit, and an EPROM. The memory in the card is divided into multiple partitions, supports different applications, achieves more than one card, and has strong security. The reader-writer adopts the mega-frequency band and magnetic induction technology, reads and writes the information in the card wirelessly and adopts a high-rate half-duplex communication protocol.

2.3 Fingerprint Identification System The fingerprint module manufactured by Taiwan Yilin Technology is composed of EVS chips. Place your finger on the lens and press the specified button to register. After extracting the key features of the input fingerprint, the burden of network transmission can be greatly reduced, and it is easy to implement remote confirmation and support the network function of the computer. Fingerprint feature information is then stored in the module's memory. Put your finger on the lens again. If it is the original finger, the green light on the module will be on. If it is not the original finger, the red light will be on. This switch information and fingerprint code can also be output via the serial port on the module. This design uses the ARAMIS technology platform to combine the single chip of the image sensing and intelligence functions with the help of the fingerprint module, so that the data transfer and exchange, fingerprint collection processing and the like have higher efficiency.

2.4 Application of digital watermarking Digital watermarking is a digital signal or pattern that is permanently identifiable in other data (host data) and does not affect the availability of host data.

There are several key technologies in the implementation process. First of all, Word, as an independently running desktop program, wants to extend its functions. The more appropriate choice is through plug-in technology, and Word itself is reserved for extensible interfaces. This gives us a certain amount of work. The degree of convenience, that is, the use of COM technology, write plug-in expansion of Word features. Secondly, after using Word's own object model to obtain email content, it is necessary to implement functions for signature and verification of the content, involving techniques such as cryptography such as hash functions and hiding bits in a picture, and make the picture uneditable. Attachment and email bond.

The digital watermark authentication module based on Word is designed and used in this system. It not only solves the problem of temporary authorization, but also has reference value for the internal file transfer of LAN.

3 system hardware and software design core control chip using inexpensive and efficient 8051 chip, through the addition of ICL232 chip for serial communication processing. At the same time, the validity of the 8051 is verified and the safe operation of the elevator and the access control model is controlled. The 8051 model used in this design is AT89s52 manufactured by Atmel. In addition, due to the high baud rate of card readers and fingerprint machines, choosing the right crystal is also key. The control program is written entirely in assembly language and the system is extremely efficient.

The main workflow of the control program of the access control module is as follows: Initialize the serial communication setting of the 51 chip, and then read the card number data sent from the card reader from the serial port and store it in a pre-opened storage area, and then pass judgment 51 specific tubes The signals of the signal lights on the fingerprint machine connected to the feet (green light is correct and red light is wrong) to determine the legitimacy of the identity. If the verification passes, then the buffer card number data is transmitted to the real-time monitoring system software of the upper computer through the serial port.

The elevator control program is basically the same as the access control module, but it does not transmit data to the host computer. It is only a single verification and operation module.

RS232 standard for serial data communication. Taking the access control module as an example, first the card number data of the card reader is received by the ICL232 chip, and is transmitted to the controller, and the signal flag of whether the fingerprint verification is correct is read at the same time (the correct green light and error red line connecting to the fingerprint module). Lamp), waiting for the controller to determine the legitimacy of the identity, then pass the data to the PC host control terminal through RS232.

The system main control software includes attendance system, security management system, monitoring system and digital watermarking system. Both use VC++ to write the main console interface in a unified way. This design makes the user interface friendly and interactive. The digital watermarking system uses Microsoft ATL technology and the development environment is Visual Studio 2003. Net generates DLL files that are loaded when Word 2000 starts. The program implements basic functions such as signature verification and temporary authorization, and it works normally in Word 2000.

4 Conclusion The design and development of this system involves assembly language, Visual C++, Protel 99SE and Maya, and many other applications. The entire security system from the elevator module to the access control module can be uniquely identified on the authentication. Real-time monitoring and authorization systems developed using digital watermarking technologies have further improved the overall security level of the system. The design of the entire system is embedded in the microprocessor, so it has a strong expansion and has a certain degree of promotion. According to different needs, it can be extended to major companies, enterprises, institutions, supermarkets, supermarkets, customs ports, parking management, warehouse management and other fields, making it an intelligent operating platform.