In this modern world wireless sensor network, plays vital role for collecting some of the important parameters like, temperature, pressure, Humidity, Level, flow, Motion of a particle, and vibration etc and to transfer those information to the base station or control room. In the case of wireless sensor network there will be number of various sensor placed in some specific high secure area or in some companies to monitor the current parameters and to react for that. Collected those information will be sent back to the base station or server, user can access that information upon their enquires or directly when some event occurs. In the case most of real time application those sensor data are not accessed from the base station or form the gateway node only. They can be directly accessed from the sensor node as Ad-Hoc Manner.
In some of the highly important application such as military surveillance, that collected data should be more secured than any other data. So we have to provide security measures to protect those data being accessed by unauthorized person. In the past five years there are been many research done to provide sensor data after user authentication. And also there have been many researches done on capability constraint of the wireless sensor network namely computation power, memory, and battery power.
In recent years Wong proposed a new scheme for wireless senor network for dynamic user authentication. And that scheme has several advantages as follows
It allows authorized user to access the data from the sensor node by ad-hoc manner upon conforming their authentication.
Computational load in this method is very little and it requires only simple operations.
Wong has claimed himself that this scheme has secured against replay and forgery attacks.
Disadvantage of the Scheme:
This scheme cannot protect the most of the unauthorized user form accessing the sensor data.
Password could be revealed from any of the sensor node in the wireless sensor network.
Users don’t have the freedom to change their password freely.
In this project to overcome the above scheme we are going to purpose you the modified scheme what be discussed above. Our modified scheme not only overcomes the above weakness it also increases the security of the security in Wong scheme. Another important feature of our modified scheme it allow the user freely to choose and change their password freely. Addition to that our proposed scheme does not require extra computation facility.
REVIEW OF WONG SCHEME
Wong, Zheng, Cao, and Wang have proposed a scheme for dynamic user authentication for the wireless sensor networks. As per this scheme authorized user can access any of the sensor data from any sensor nodes in the wireless sensor network by making use of their mobile devices like mobile phones, Laptop, PC’s etc.
Suppose let we say that a user want to access the sensor node first they have to access a sensor data, first they must register at the senor gate way node via secure channel. After completion of the successful registration, authorized user can login at any of the nearest login node and can access senor data.
This Scheme is divided into three main phases namely
Registration Phase
Login Phase
Authentication Phase
Registration Phase
Let we assume our self that registration interface is launched on a user mobile device. First user has to submit their user ID and password at the senor gateway for registration purpose. Then the gate way starts to compute the user ID and password for the registration process. Sensor gateway collects the data like user ID password and the gateway computed data and places it in a database. After placing those data in the database gateway has to inform the successful registration to the user.
Login Phase
Whenever a user want to access the sensor data from any node. First they have to type submit their user ID and password to the sensor login node. Then the sensor node checks whether the given ID and password is in the data sets or not. Suppose if the user name and the password is not there in the datasets it will reply that Msg(Reg_ Login). Let we say the input data what we get form the user is there is there in the data sets then the login nodes send all the information to the Gateway for authentication.
Authentication Phase
After receiving all the information from the login node to the Gateway. IT checks whether data is there in database or not, if the data is not there in data base it send back the message Msg(Reg_Login) to the login nodes. Suppose if the user name and password is correct gateway will send the acknowledgement message to the login node. And the login node further sends the acknowledgement message to the user.
Disadvantage
Even though Wong proposed a dynamic user authentication scheme to access the sensor nodes with user authentication it has several security weaknesses in that scheme.
This scheme cannot withstand against replay attacks. Replay attacks can be defined as the suppose if a attacker tries to replay the same message obtained from the previous session in that wireless sensor network. So as per out discussion above if the attacker can successfully login to the sensor network through replay so this scheme cannot withstand replay attack.
This system doesn’t have the capability to withstand forgery attack. Suppose if an attacker listens to the login message without the knowledge of the authorized user they can even change that login message to their options to access the resources of the remote system.
In this scheme password of the any user can be made visible from any nodes. Even though we are transmitting password through the secure channel in both registration and login phases, every password will be still known to the sensor gateway ant too the login nodes in pain text. So as per our above discussion there is no protection mechanism to control or protect leaking out of password when the gateway and login nodes are concerned.
In the case of Wong scheme if the password is fixed once it cannot be changed again and again. If they are fixed once they will be kept aside. So obviously fixed password have many security attacks than the normally changed password.
THE IMPROVED SCHEME
In this chapter we present you the modified scheme of you Wong scheme that not only over comes the weakness of the existing scheme and also It will increase the security of Wong scheme. Our proposed scheme as four important stages namely
Registration Phase
Login Phase
Authentication Phase
Password changing Phase
Here registration and password changing operation or done in secured channel, and our different phases as Follows
Registration Phase
Whenever the user submits their user name and password to a sensor gateway in a wireless sensor network for their registration, gateway stores those data in it s data base. After the successful completion of the registration node gateway will acknowledge back the users. Finally all those information will be spread throughout all the sensor nodes.
Login Phase
First the user has to submit their data (User name) to the login phase. After receiving the user name at login node, the login nodes checks whether the received data present in the datasets of not. If the data does not present in the login node it will reply the user as Msg(Reg_Login) . Suppose if all the information what we get from the user are correct it compute that information and send that back to the gateway for authentication.
Authentication Phase
After receiving the computed message from the login phase, the gate way checks whether the data what we got from the login phase exist in the database or not, if it so it will reply back the user as Msg (REG_LOGIN). Suppose if the data what we got from the login phase is correct gateway will reply login phase with an acknowledgement signal named Msg(ACC_LOGIN), Now user will get an acknowledgement signal form the login phase as Msg(ACC_LOGIN).
Password Changing Phase
Important concept in our improved scheme is that password changing concept. If the user feel that his password is know by someone else than him and if he want to change the password they can change the password easily. If a user decides to change his password he or she as to submit their old password , user Id and a new password to the sensor gateway, after receiving those information sensor whether that data exist in the data base or not, if it so old password will be changed to the new one if not the gateway reply to the user with a message Msg(REG_CHANGE) stating password cannot be changed.
Analysis
Security Analysis
Our enhanced scheme consist can with stand for all the security attacks. The advantage of the proposed scheme over the present scheme stated below.
Our modified scheme can protect against replay attacks so the attacker cannot access the user name or password illegally through the replay attacks
Our scheme can also protect against the forgery attacks that is suppose if an attacker taken the list which consist the information about the user name and password of the authorized user they were not able to get the user name and password information form that node because information stored will be in some algorithmic value.
Here password cannot be kept visible in any of the sensor nodes. In both the registration and login phase in order to make the password secret it will be passed has some algorithmic form than the plain text.
One of the most important feature of this scheme user can change their old password with their new password via secure radio channel. This scheme has the capability to protect the new password too.
