CN102355356A - Asymmetric encryption method suitable for ZIGBEE wireless meter reading - Google Patents

Abstract

The invention discloses an asymmetric encryption method suitable for ZIGBEE wireless meter reading, which comprises the following the following steps that: step 1, when hardware is initialized, the same public key and private key are generated by specific p, q and e in an RSA (Rivest-Shamir-Adleman) algorithm in a central node and a terminal node, accordingly, a public key and a private key are stored in the central node and the terminal node, the public key is used for encrypting messages, and the private key is used for decrypting the messages; step 2, when the central node sends messages to the terminal node, the data is encrypted by the public key firstly, and then the messages are sent to the terminal node; and step 3, after the terminal node receives the data, the data is decrypted by the private key and are restored into original messages; and when the terminal node sends the messages to the central node, the step 2 to the step 3 is adopted. The reliability of the symmetric encryption method of RSA and the characteristic that each frame data is less in ZIGBEE wireless transmission are combined to effectively improve the security of wireless transmission.

Description

A kind of asymmet-ric encryption method that is applicable to the ZIGBEE radio meter register

Technical field

The present invention relates to a kind of radio communication and transmission encryption method.Be specifically related to a kind of asymmet-ric encryption method of the ZIGBEE of being applicable to radio meter register.

Background technology

The ZIGBEE technology is a kind of two-way wireless communication technology towards automation and controlled in wireless of rise in recent years.It has closely, low data rate, low complex degree, low-power consumption, characteristics cheaply.Spendable frequency range that ZIGBEE is wireless has 3, is respectively ISM (the Industrial Scientific Medical) frequency range of 2.4GHz, the 915MHz frequency range of the U.S. and the 868MHz frequency range in Europe.Adopting the 2.4GHz frequency range in China, is the frequency of exempting to apply for and exempt from usage charges.Its transmission rate is 20kb/s ~ 250kb/s, and transmission range is 10m ~ 75m.It coordinates to realize communication each other according to the 802.15.4 standard between thousands of small transducers.These transducers only need energy seldom, through radio wave data are passed to another transducer from a transducer with the mode of relay, so communication efficiency is very high.And the characteristics of lower data speed and less communication range have determined it to be suitable for carrying the less business of data traffic, and main application fields comprises occasions such as data acquisition, wireless industrial control, consumer electronics device, automotive automation, family and building automatic, medical equipment control, telecommunication network control.In addition, whole advantages that ZIGBEE has taked the strong radio physical layer of IEEE 802.15.4 to be had: power saving, simple, specification that cost is low have increased logical network, network security and application layer.

The ZIGBEE safe practice is based on that one group 128 key realizes, uses the AES-128 block encryption.In data encryption process, can use three kinds of basic keys.Be respectively master key, link key and netkey.Master key can be installed when device fabrication, also can pass through the trust center setting, or based on the data of user capture, for example, PIN (PIN), password and password etc.Master key is the basis of two equipment long-term safety communications, also can be used as general link key and uses.So, must safeguard the confidentiality and the correctness of master key.When in network transmission process, adopt master key can stop eavesdropping.Link key is shared by two equipment in a PAN network, and it can be set up through master key, also can when device fabrication, install.Netkey can pass through the trust center setting, also can when device fabrication, install.It can be applicable to data link layer, network layer and application layer.Link key and netkey constantly periodically upgrade.When two equipment all have these two kinds of keys, adopt link key to communicate.Because security mechanism is based on shared key, the safety guarantee of network mainly depends on the storage security of initialization safety and all keys.

Yet the use of symmetric key need be distributed on up to a hundred the device nodes in application, and there is very big potential safety hazard in this, and more defectives of AES encryption method can manifest afterwards day by day.All use single symmetric encryption method perhaps can become the weak spot in the ZIGBEE safeguard construction to data encryption and interchange key.Based on this reason, use asymmet-ric encryption method to come the distributed key expectation to expand to some extent.

Summary of the invention

The objective of the invention is to solve the single shortcoming of symmetric encryption method key, propose a kind of asymmet-ric encryption method of in ZIGBEE, using.

The technical scheme that the present invention adopts is: utilize the RSA asymmetric methods, the data of sending are encrypted with PKI at transmitting terminal, the data that receive are deciphered with private key at receiving terminal.Method comprises following content:

A kind of asymmet-ric encryption method that is applicable to the ZIGBEE radio meter register may further comprise the steps:

Step 1: Centroid and terminal node are when hardware initialization; Use p specific in the RSA Algorithm, q and e to generate identical PKI and key; Centroid and terminal node have all been preserved a PKI and key like this, and PKI is used for to message encryption, and private key is used for to decrypt messages;

Step 2: when the center node sends message to terminal node, use public-key earlier, send to terminal node then to data encryption;

Step 3: after terminal node is received data, use the private key data decryption and be reduced into origination message.

When terminal node sends message to Centroid, also will adopt identical step.

The conspicuousness progress and the characteristics of technical scheme of the present invention are mainly reflected in: the advantage of the reliability of RSA asymmet-ric encryption method is combined with the few characteristics of the every frame data amount of ZIGBEE wireless transmission, effectively improve the fail safe of wireless transmission.Because the 20-250kb/s overall transmission rate of ZIGBEE network, when the number of nodes in the network was 100 nodes, the speed of each node was less than 2kb/s.And the key length of rsa encryption needs at least 1024 bits, and receive the bigger restriction of view data this moment, and the ZIGBEE network will not carry this transmission demand.Therefore the present invention adopts the meter reading data (less than the kb level) of the minimum data volume of ZIGBEE Network Transmission, and network capacity can reach the scale of 100 nodes, and the key length of RSA can reach 2048 bits, has strengthened fail safe.

Embodiment

So-called asymmetric, be meant that this method needs pair of secret keys, use one of them encryption, then need use another to decipher.The RSA method is wherein a kind of asymmetric cryptography method.

One: generate PKI and private key

1. get two big at random prime number p and q, p is not equal to q, calculates N=p*q;

2. according to Euler's function, be not more than N and be (p-1) * (q-1) with the relatively prime integer number of N;

3. integer e of picked at random is with (p-1) * (q-1) is relatively prime, and e is less than (p-1) * (q-1);

4. calculate d:d*e ≡ 1 (mod (p-1) * (q-1)) with following formula;

5. the record of p and q is destroyed.

Thus, (N e) is PKI, and (N d) is private key, and (N is secret d).(N e) encrypts the data of sending to transmit leg, and (N d) deciphers the data that receive with private key with PKI.

Two: encrypting messages

Suppose that Centroid wants to send message m to terminal node, it know PKI (N, e).Its use converts m into an Integer n less than N with the form that terminal node is arranged in advance, such as m is represented heuristicimal code, these heuristicimal codes is connected together form a numeral then.With following this formula n is encrypted as c then:

Centroid just can send to terminal node with c after calculating c.

Three: decrypt

Terminal node receives and just can utilize private key behind the message c (N d) decodes.Can convert c into n with following formula:

After obtaining n, terminal node can be reduced into n origination message m.

The easy explanation with a long history of RSA method, and can be used as encryption and decryption simultaneously.And the speed of RSA has determined it generally to be used for the low volume data encryption.

In sum, after the RSA asymmet-ric encryption method, can in the ZIGBEE wireless network, transmit data more safely.

The above; It only is preferred embodiment of the present invention; Be not that the present invention is done any pro forma restriction, every foundation technical spirit of the present invention all still belongs in the scope of technical scheme of the present invention any simple modification, equivalent variations and decoration that above embodiment did.

Claims (1)

1. asymmet-ric encryption method that is applicable to the ZIGBEE radio meter register may further comprise the steps:

Step 1: Centroid and terminal node are when hardware initialization; Use p specific in the RSA Algorithm, q and e to generate identical PKI and key; Centroid and terminal node have all been preserved a PKI and key like this, and PKI is used for to message encryption, and private key is used for to decrypt messages;

Step 2: when the center node sends message to terminal node, use public-key earlier, send to terminal node then to data encryption;

Step 3: after terminal node is received data, use the private key data decryption and be reduced into origination message;

When terminal node sends message to Centroid, also adopt the step of step 2 to step 3.