This document proposes a computation-efficient method for multicast key distribution that significantly reduces the computation load on group members compared to existing schemes. It introduces a scheme where a shared secret key is used between encryption and decryption when transferring messages from the source to multiple receivers. This key is established using the MD5 cryptography algorithm. It also generates multiple session keys to avoid communication complexity, with a new key generated when members leave a session. The objective is to securely transfer messages from one sender to multiple receivers using multicast networking with reduced computation complexity for battery-powered devices.

1. Computation-Efficient Multicast Key Distribution
1.Introduction
1.1 Abstract:
Using Multicast key distribution computation complexity is significantly reduced.
It drastically reduces the computation load of each group member compared to existing
schemes employing traditional encryption algorithms. Such a scheme is desirable for
many wireless applications where portable devices or sensors need to reduce their
computation as much as possible due to battery power limitations. Easily combined with
any key-tree-based schemes, this scheme provides much lower computation complexity
while maintaining low and balanced communication complexity and storage complexity
for secure dynamic multicast key distribution.
1.2 ABBREVIATIONS
MD5 – Message-Digest algorithm 5
DSK Different Session Key
1.3 References
http://tldp.org/HOWTO/Multicast-HOWTO.html
http://www.ipmulticast.com/
http://www.cdt.luth.se/~peppar/java/multicast_example/
http://www.cdt.luth.se/~peppar/java_multicast/
http://java.sun.com/docs/books/tutorial/networking/datagrams/broadcasting.html

2. 2. Overview of Existing System:
In existing system unicast method has been used. In this method message can be
transferred to only one user at a time. There is no security measure while transferring
messages hence data loss may occur because of hackers. Communication complexity
occurs due to Single session key method.
3. Objective of Proposed System:
In Proposed system Multicast Re-keying method has been used. Using this
method message can be transferred to multiple users at a time. Secret key is generated to
avoid data loss while transferring messages by using Cryptography method.
Communication complexity is circumventing by providing multiple session key.

3. 4.2 Software Specification:
Software Interfaces:
Operating System
: Win2000/Win xp
Programming Package
: JAVA / J2EE
Tools
: Eclipse.
SDK
: JDK1.5.0
4.3 Hardware Specification:
Hardware Interfaces:
Processor Type
: Pentium -IV
Speed
: 2.4 GHZ
Ram
: 128 MB RAM
Hard disk
: 20 GB HD

4. Project Modules
 User interface design
 Transferring message using multicast
 Key establishment using MD5 cryptography algorithm
 Session key generation for multicast receivers
 Audio chatting
User interface design:
In this Module, Design the interface for the user to interact with the application.
Each and every software application needs fine steps to interact with end users of the
application. In this application the interactions with end users are made under AWT
concepts. User should enter the particular Internet protocol address of server to transfer
message. The user should enter his/her user name to adhere the chat room.
Transferring message using multicast:
In this method, you can transmit data or messages to all destination host
machines, which has been interested an appropriate multicast group. The sender
generates only one data stream
But it delivered to all destination hosts. It supports one-to-many data delivering networks.
Multicast delivers a data or information simultaneously to all interested destination hosts
machines. The multicast methodologies are used in case of teleconferencing and
videoconferencing. The teleconferencing and videoconferencing machines transmit data
simultaneously to all interested parties present in the same group.
Multicast provides the best features to unicast and broadcast because, here neither carries
the burden of data to delivering all hosts nor misses-utilize the entire network. Users are
joined in the multicast groups to follows an appropriate standard like: IP Multicast and
Mbone.
Key establishment using MD5 cryptography algorithm:

5. Shared secret key is used between encryption and decryption of message being
transferred from source to number of receivers.
Cryptographic Implementation:
To prevent the attacker (Middle-man-attack, etc.) from reading the data, we go for
the encryption and decryption of the data. Here we use the MD5 symmetric key
algorithm for secure message transfer. Since there is a separate common key for each pair
of user, the data is secured from others.
Session key generation for multicast receivers:
Every chat room should have an independent session to transfer data between
multiple users. Hence each session thus needs a new key that is only known to the current
session members, i.e., session keys need to be dynamically distributed to authorized
session members. When any one of the old member logout from the chat room, session
key has been canceled for every one and a new session key is generated for the remaining
members.
Audio Chatting:
User can interact by audio chatting. By giving the IP of the user whom want to
interact can have a voice chat. VOIP (Voice over internet protocol) is used to chat. Audio
chat is processed in WAN in former but it’s implemented in LAN also using UDP (User
Datagram Protocol). Transferring audio is in the form of encryption and decryption form
so it’s used to avoid third man interaction.

6. ScreenShots :