CN203659084U

CN203659084U - Access device for encrypting wiegand protocol signal

Info

Publication number: CN203659084U
Application number: CN201320836252.9U
Authority: CN
Inventors: 霍建烨; 梁穗詠; 李伟; 吴正志
Original assignee: TONGFANG RUIAN TECHNOLOGY Co Ltd
Current assignee: TONGFANG RUIAN TECHNOLOGY Co Ltd
Priority date: 2013-12-18
Filing date: 2013-12-18
Publication date: 2014-06-18
Anticipated expiration: 2023-12-18

Abstract

The utility model discloses an access device for encrypting a wiegand protocol signal, and belongs to the technical fields of door control. The access device provided by the utility model comprises a door control card reader and an access controller, and the access device is structurally characterized in that the door control card reader comprises a card reader CPU (Central Processing Unit), an encryption module, a card reader end secret key and a clock chip; the card reader CPU is connected with the clock chip and the encryption module respectively through a data bus, and the card reader end secret key is stored in a data storage region of the card reader CPU; the access controller comprises a controller CPU, a decryption module and a controller end secret key, the decryption module and the controller CPU are connected with each other through the data bus, and the controller end secret key is stored in a data storage region of the controller CPU. Compared with the prior art, the access device provided by the utility model has the advantages that the confidentiality during the data transmission is guaranteed, attacking means such as eavesdrop and data falsification are effectively prevented, and the legality and security of the data is fundamentally guaranteed.

Description

A kind of entrance guard device to Wiegand protocol signal encryption

Technical field

The utility model belongs to gate inhibition's technical field, the entrance guard device particularly data-signal of Wiegand protocol transmission being encrypted.

Background technology

In prior art, known gate control system comprises access-control card reader and access controller, and the data-signal of communicating by letter between access-control card reader and access controller adopts Wiegand protocol to encode, and this is a kind of communication protocol of one-way transmission data, as shown in Figure 1.Access-control card reader is connected with access controller by data line, and data transfer mode is unidirectional to send to access controller by access-control card reader.Access card is put into access-control card reader and gets on to swipe the card, after access-control card reader checking card is legal, just use Wiegand protocol to encode the card number of this card, send to access controller to carry out authority judgement.But, the data of Wiegand protocol transmission are expressly, and the communication line of access-control card reader and access controller be easy to can be reequiped and access illegality equipment, thereby the equipment of victim intercepts the legal card number data of transmission, even directly the legal card number data that intercept are sent to access controller by illegality equipment, reach the object of illegally opening the door.Conventionally, adopt the gate control system of Wiegand protocol can not distinguish card number data that access-control card reader sends to access controller be whether legal, be not tampered, this has brought potential safety hazard to gate control system, easily causes illegal person's invasion.

Summary of the invention

For above-mentioned the deficiencies in the prior art, the purpose of this utility model is to provide a kind of entrance guard device to Wiegand protocol signal encryption.It can not only ensure the confidentiality during data transmission, and can effectively prevent the attack meanses such as eavesdropping and data falsification, fundamentally ensures legitimacy and the security of data.

In order to reach foregoing invention object, the technical solution of the utility model realizes as follows:

To an entrance guard device for Wiegand protocol signal encryption, it comprises access-control card reader and access controller.Its design feature is that described access-control card reader comprises card reader CPU, encrypting module, card reader end key and clock chip.Card reader CPU is connected with encrypting module with clock chip respectively by data bus, and card reader end key storage is in the data storage area of card reader CPU.Described access controller comprises controller CPU, deciphering module and controller end key, and deciphering module is connected by data bus with controller CPU, and controller end key storage is in the data storage area of controller CPU.

The utility model, owing to having adopted said structure, can adopt in the process of Wiegand protocol transmission at entrance guard device, and the data of transmission are carried out to dynamic encryption, and the card number data that guarantee transfers to access controller from access-control card reader are safe and effective.Meanwhile, the utility model can prevent the attack meanses such as eavesdropping and data falsification effectively, fundamentally ensures the security of gate control system transmission data.

Below in conjunction with the drawings and specific embodiments, the utility model is described in further detail.

Brief description of the drawings

Fig. 1 is the structural representation of entrance guard device in prior art;

Fig. 2 is the utility model structural representation;

Fig. 3 is workflow diagram of the present utility model in embodiment.

Embodiment

Referring to Fig. 2, the utility model comprises access-control card reader and access controller to the entrance guard device of Wiegand protocol signal encryption.Access-control card reader comprises card reader CPU1, encrypting module 11, card reader end key 12 and clock chip 13, card reader CPU1 is connected with encrypting module 11 with clock chip 13 respectively by data bus, and card reader end key 12 is stored in the data storage area of card reader CPU1.Access controller comprises controller CPU 2, deciphering module 21 and controller end key 22, and deciphering module 21 is connected by data bus with controller CPU 2, and controller end key 22 is stored in the data storage area of controller CPU 2.

Referring to Fig. 3, the encipher-decipher method step of the entrance guard device of the utility model to Wiegand protocol signal encryption is:

1) at initial phase, the time initial value of clock chip 13 is synchronizeed with the system time of access controller, ensure that clock chip 13 and the time error of access controller are less than 100ms.At initial phase, card reader end key 12 and controller end key 22 are set to identical value equally, are stored in the middle of data storage area separately.

Encrypting module 11 and deciphering module 21 are selected identical symmetry algorithm computing module, for example, use and support that the close SM1 algorithm of state is an optimum selection.Encrypting module 11 and deciphering module 21 and the separately communication modes of CPU can use serial port protocol.Because the card number data length that will encrypt is generally 4 bytes, generally 8 bytes or 16 bytes and symmetrical enciphering and deciphering algorithm carries out the minimum length of once-through operation, so can fill the card number data byte of padding that will encrypt, to reach the length that can carry out once symmetrical encryption and decryption computing, the value of byte of padding can be any, but will ensure to use identical value on encrypting module 11 and deciphering module 21.

2) access-control card reader obtains the card number of card.

3) access-control card reader gets Date and the time from clock chip 13, and the value of time is accurate to second.

4) with encrypting module 11, this date and time value is encrypted, obtains interim session key one.

5) access-control card reader uses the card number data after a pair of filling of interim conversation key that obtains to be encrypted, thereby obtains ciphertext card number.

6) access-control card reader is transferred to access controller by Wiegand protocol communication line ciphertext card number.

7) after access controller is received encrypt data, date and time is encrypted with card reader end key 12, obtains the secret key two of interim conversation.

8) now carry out time-sampling apart from access-control card reader and pass by a period of time, but this section of consuming time can being controlled in 1 second that is to say, the time value of access controller sampling is likely identical with the time value of access-control card reader, also may slow 1 second.So, in implementing, just need correction, access controller can all carry out decrypt operation one time to these two kinds of possible time values, in two decrypted results, the value that byte of padding is set before being is thought legal result, so just can decipher accurately the plaintext that obtains card number data.

Use in the process of the utility model system signal transmission, the data that adopt are ciphertexts, and each key of encrypting is the dynamic key disperseing by the time, the utility model there is never repeatability, so can fundamentally solve the security threat that the means such as eavesdropping, forgery in gate control system cause.

Claims

1. the entrance guard device to Wiegand protocol signal encryption, it comprises access-control card reader and access controller, it is characterized in that, described access-control card reader comprises card reader CPU(1), encrypting module (11), card reader end key (12) and clock chip (13), card reader CPU(1) be connected with encrypting module (11) with clock chip (13) respectively by data bus, card reader end key (12) is stored in card reader CPU(1) data storage area; Described access controller comprises controller CPU (2), deciphering module (21) and controller end key (22), deciphering module (21) is connected by data bus with controller CPU (2), and controller end key (22) is stored in the data storage area of controller CPU (2).