Secure Data Transmission using Alternate Path in Ad hoc Network

 Secure Data Transmission using Alternate Path in Ad hoc Network

Er. Isha Nagpal

Assistant professor,DCSE, PPIMT,Hisar

isha.n.ppimt@ppu.edu.in

 

Learning Objectives:

·        Introduction to Mobile Ad hoc Network

·        Types of Routing In MANET

·        Traditional Approach of Data Transfer in Unicast Transferring

·        Security Requirements of Mobile Ad-Hoc Network

Introduction

Mobile ad hoc networks (MANETs) consists of a collection of wireless mobile nodes which dynamically exchange data among themselves without the reliance on a fixed base station or a wired backbone network. The ad-hoc network provides lack of secure boundaries. An ad hoc network is the cooperative engagement of a collection of mobile nodes without the required intervention of any centralized access points i.e. no access points passing information between participants act as LAN which is built spontaneously as devices connected instead of relying on base stations to coordinate the flow of messages to each node in a network.

                 In MANETs communication between nodes is done through the wireless medium. Because nodes are mobile and may join or leave the network. MANETs have a dynamic topology. Nodes that are in transmission range of each other are called neighbours. Neighbours can send data directly to each other. However, when a node needs to send data to another non-neighbouring node, the data is routed through a sequence of multiple hops, with intermediate nodes acting as routers.

Types of Routing in MANET

1.1    Unipath Routing in MANET

In unipath routing, only a single route is used between a source and destination node. Routing protocols are used to find and maintain routes between source and destination nodes.

Two main classes of ad hoc routing protocols are table-based and on-demand protocols:

a) Table Based Protocols: Each node maintains a routing table containing routes to all nodes in the network. Nodes must periodically exchange messages with routing information to keep routing tables up-to-date. Therefore, routes between nodes are computed and stored, even when they are not needed.

b) On Demand Protocols: Nodes only compute routes when they are needed. On-demand protocols consist of the following two main phases:

1. Route discovery: It is the process of finding a route between two nodes.

2. Route maintenance: It is the process of repairing a broken route or finding  a new route in the presence of a route failure.

Two of the most widely used protocols are the Dynamic Source Routing (DSR) and the Ad hoc On-demand Distance Vector (AODV) protocols. AODV and DSR are both on-demand protocols.

Dynamic Source Routing: DSR is an on-demand routing protocol for ad hoc networks. Like any source routing protocol, in DSR the source includes the full route in the packets’ header. The intermediate nodes use this to forward packets towards the destination and maintain a route cache containing routes to other nodes.

Route discovery: If the source does not have a route to the destination in its route cache, it broadcasts a route request (RREQ) message specifying the destination node for which the route is requested. The RREQ message includes a route record which specifies the sequence of nodes traversed by the message. When an intermediate node receives a RREQ, it checks to see if it is already in the route record. If it is, it drops the message. This is done to prevent routing loops. If the intermediate node had received the RREQ before, then it also drops the message. The intermediate node forwards the RREQ to the next hop according to the route specified in the header. When the destination receives the RREQ, it sends back a route reply message. If the destination has a route to the source in its route cache, then it can send a route response (RREP) message along this route.       Route maintenance: When a node detects a broken link while trying to forward a packet to the next hop, it sends a route error (RERR) message back to the source containing the link in error. When an RERR message is received, all routes containing the link in error are deleted at that node.

Ad Hoc On Demand Distance vector: AODV is an on-demand routing protocol for ad hoc networks. AODV uses hop-by-hop routing by maintaining routing table entries at intermediate nodes.

Route Discovery: The route discovery process is initiated when a source needs a route to a destination and it does not have a route in its routing table. To initiate route discovery, the source floods the network with a RREQ packet specifying the destination for which the route is requested. When a node receives an RREQ packet, it checks to see whether it is the destination or whether it has a route to the destination. If either case is true, the node generates an RREP packet, which is sent back to the source along the reverse path. When the source node receives the first RREP, it can begin sending data to the destination.

Route Maintenance: When a node detects a broken link while attempting to forward a packet to the next hop, it generates a RERR packet that is sent to all sources using the broken link. The RERR packet erases all routes using the link along the way. If a source receives a RERR packet and a route to the destination is still required, it initiates a new route discovery process.

1.2   Multipath Routing in MANETs

Standard routing protocols in ad hoc wireless networks, such as AODV and DSR, are mainly intended to discover a single route between a source and destination node. Multipath routing consists of finding multiple routes between a source and destination node.

1.2.1 Route Discovery and Maintenance: Route discovery and route maintenance consists of finding multiple routes between a source and destination node. Multipath routing protocols can attempt to find node disjoint, link disjoint, or non-disjoint routes. Node disjoint routes, also known as totally disjoint routes, have no nodes or links in common. Link disjoint routes have no links in common, but may have nodes in common. Non-disjoint routes can have nodes and links in common. From a fault tolerance perspective, more reliable paths should be selected to reduce the chance of routes failures. Path selection also plays an important role for QoS routing. In QoS routing, only a subset of paths that together satisfies the QoS requirement is selected.

1.2.2 Split Multipath Routing: Split Multipath Routing (SMR) proposed  is an on-demand multipath source routing protocol. SMR is similar to DSR, and is used to construct maximally disjoint paths. Unlike DSR, intermediate nodes do not keep a route cache, and therefore, do not reply to RREQs. This is to allow the destination to receive all the routes so that it can select the maximally disjoint paths. Maximally disjoint paths have as few links or nodes in common as possible. Duplicate RREQs are not necessarily discarded.

2. Security Issues in Mobile Ad hoc Network

As the data is transmitted over the adhoc there is no centralized manager for the adhoc network, because of this the chances of Intruder attach increase. The Attack can be in case of Unipath routing or in multipath, Even the topology is dynamic still it has many flaws in terms of security.

The Intruder attack is on the algorithmic approach of data transfer.  Some of the common attacks on security are:

1. Attacks using modification- False Sequence number

Malicious nodes can cause redirection of network traffic and DoS attacks by altering control message fields. In AODV, any node may divert traffic through itself by advertising a route to a node with a desti_sequence_num greater than the authentic value.

2. Attacks using modification – False hop counts.

AODV uses the hop count field to determine a shortest path Malicious nodes can set hop count to zero. DSR uses source routes in data packets DoS attack can be launched in DSR by altering the source routes in the packet headers.

3.Attacks using modification tunneling

A tunneling attack is where two or more nodes may collaborate to encapsulate messages between them.

Traditional Approach of Data Transfer in Unicast Transferring

According to a standard approach of communication between two nodes it is always based on the shortest path. The shortest path gives number of benefits like Easy implementation, Fast and reliable data transfer between nodes. One of the common algorithm for selecting the path is given below:

Path(A,n)

/* A is the Weighted graph of n size to represent the Ad hoc Network*/

{

      Step 1. Generate the neighbour list for the source node and put it in the matrix.

Step 2 .Starting from the first neighbour generate the next neighbour.

Step 3. Check if that neighbour already exist in the list if yes than it is a loopback and go to end;

Step 4. Generate the route from all the neighbours for the destination and continue  on that path.

Step 5. Generate the route to destination from all neighbours where ever possible.

Step 6. Compare the route length generated by all the possible routes. Compare all the routes in the distance matrix and choose the path to destination which has the lowest path length.

}

This approach of data transfer is very common in case of dynamic topology like the sensor network.  But as the intruder attacks according to the same approach it gives the very high chances of Data hack.

In this diagram, there are number of possible paths and as a reliable and fastest path , the client will always select the shortest path .But this approach has some problems based on security and reliability. Some of them are as follows:

1. Select One Shortest path

• Use of wireless links in shortest path susceptible to link attacks
• Relatively poor protection as in Battlefields.
• Passive eavesdropping
• Attacks from compromised attacks.

2. Multi Path

• Flooding: As an incoming packet is sent on all incoming links,it limit the number of hops to avoid infinite loops or forward packets only once using a packet ID or only on selected links in the right direction
• Multicasting: Terribly expensive in terms of resource utilization and results in minimum delay

 We are suggesting the alternate path approach that is close to the shortest path and more reliable and secure.

Security Requirements of Mobile Ad-Hoc Network

Requirements of Ad-Hoc Network are:

• Route signalling can’t be spoofed

• Fabricated routing messages can’t be injected into the network

• Routing messages can’t be altered in transit

• Routing loops can’t be formed by through malicious action

• Routes can’t be redirected from the shortest path by malicious action

• Unauthorized nodes should be excluded from route computation and discovery.

Path A to B

/* A is the Adjacency matrix representation of given network, n is the no of nodes and a,b are two nodes between we have to transfer data*/

Step 1. Give the range of the network node and set all other elements that are outside  the range to 0.

Step 2. Find the Neighbour of Each node of network starting from node a to node b.

Step 3.Find the shortest path from source to destination and store it in an array called array[ ].

Step 4. Search the neighbour list and pick a random node from the list and put that node in the array.

Step 5. Compare the random node with all the elements of the shortest path array. If the array[top] element matches with any of the elements in the list then Make the entry corresponding to that node in neighbour array.

Step 6. Compare the neighbour list of the generated node with all the elements of array otherwise pick a random node from the list and put it in the array

}

Finally we get the list of nodes that provide a safe path in case of unicast, this pass is very closer to the shortest path but does not include any node from the shortest path list because of this it provide the secure transmission on the algorithm implementation attack of the Intruder.

Roof on top: For a neat realty search

Roofontop is integrated with Google Maps, and this enables one to see where exactly the property is located, as well as what exactly is in the neighborhood


Like for most other things, many Indians turn to the Internet when they're looking to buy, sell or rent a property. Not that it avoids the hassle of dealing with agents - a majority of the listings on real estate portals are by agents - but it at least saves you the hassle of going through classifieds.
For years, there have been very few players in the online segment when it comes to real estate portals. 99acres.com, magicbricks.com and makaan.com are the more popular websites, which, frankly, look like a maze of property advertisements. A new player, roofontop.com, has ventured into the space now. But how different is it from the other online options?
For starters, roofontop is a neat-looking portal. It is integrated with Google Maps; so, you can see where exactly the property is located, as well as what exactly is in the neighbourhood. Like other portals, there's a search column where you need to feed in details - size of the house, budget, locality - to get the results you're looking for. Roofontop also has a "services" features where you can get a list of architects, interior designers, electrical services and even lawyers! Like its competitors, it also has a host of links to help find home loans and finance options.
There's also something called a "platinum agent" network, which has agents who are not your typical hole-in-the-wall agents. The portal claims these agents have been given special training on how to deal with customers and have better reputation.

Roofontop has been started by Alin Kapilashramai, who is the founder of the portal and wants to give a better experience to customers. While other websites have a pan-India presence - in terms of property listings - Roofontop only has listings from Delhi and NCR. It has plans to expand its operations to other cities as well.

The map feature is certainly the most standout thing about roofontop. In fact, the regular search, at times does have a few glitches. We tried looking for properties in Noida and Gurgaon and on at least four occasions, it asked us to enter the maximum price again, despite keying it correctly. The map, however, worked very smoothly.

The map is dotted with small house icons indicating where properties are available. Once you click on the icon, it will tell you if the property is a two-bedroom house or a three-bedroom one. It also tells you about the rent and the per square foot price the property commands. It's intuitive in the sense that it automatically detects the location from where you're browsing and shows property of nearby areas as well.

Roofontop certainly is better in terms of look than the 99acres.com or even magicbricks.com. The maps feature, however, will be a bit tricky to expand to other cities. It has a lot of pictures and videos to support the properties, which is another thing the competitors lack.

Indian digital user warms up to tablets

Indian digital consumer is adapting fast to tablet use. For the April-June quarter as many as 70 international and domestic vendors shipped 1.15 million units of tablets.

The overall growth in shipments of Tablets in the India market registered at 107.4% year-on-year (2Q CY 2013 over 2Q CY 2012) growth, but a more moderate 27.2% quarter-on-quarter (2Q CY 2013 over 1Q CY 2013) increase due to seasonal factors, according to CMR’s India Quarterly Tablet PC market review for second quarter.

“For a few quarters now, we have seen over a million shipments per quarter of Tablets with only 1Q 2013 being the exception. 2Q 2013 results have again shown that 1 million units a quarter is a sustainable number, which is a healthy indicator about adoption of the Tablet form factor in India in less than three years. If this trend continues to build up, I see adoption picking up and just a few quarters from now we should see shipment of significantly higher volumes,” said Faisal Kawoosa, Lead Analyst, CMR Telecoms Practice.

The top three vendors, led by Samsung, Datawind and Micromax, corner 43.4% market share. Though the Indian market had plethora of vendors, only 13 vendors shipped in significant volumes of more than 20,000 units during the period. Top five vendors have market share of 55.8% and top 13 players have a market share above 80%.

Almost 80% of the Tablet models launched during this period were with both 3G and Wi-Fi connectivity, leading to a growth of 103% in shipments of 3G Tablets.

“This is the first quarter when Tablets with dual-SIM functionality arrived in the India market, thereby giving vendors an additional specification to differentiate their offerings. It will be interesting to see if there are any significant shifts in Tablet shipments in the forthcoming quarters. With the requirement for mandatory adherence to BIS certification it will be difficult for vendors who do not get their products BIS-approved to sell in India. This may lead to some consolidation in the India Tablets market in the short- to medium-term,” said Tarun Pathak, Analyst, CMR Telecoms Practice.

Vendor	Share(%)
Samsung	21.2
Datawind*	12.5
Micromax	9.7
*excludes shipment of Aakash tablets

Mahindras step into technical education starts campus in Hyd

 

The Mahindra Group has marked its entry into the technical education space by setting up an engineering institution in Hyderabad. Mahindra École Centrale has been set up in collaboration with the France-based Ecole Centrale and Jawaharlal Nehru Technological University-Hyderabad. Tech Mahindra executive vice chairman Vineet Nayyar said the institute would facilitate extensive industry-university collaboration to generate global soft-skilled tech managers, which is important for India to maintain a competitive edge. The institute will also bring upfront industry managerial practices to practising engineering graduates.

The campus would start absorbing students from the academic year 2014 with an intake of 300 for the initial batch and in the years would raise this to 2,500. To start with, it would consider the Indian Institute of Technology (IIT-JEE) score for admissions. The campus is affiliated to JNTU-Hyderabad.
Nayyar on Friday said India despite having numerous engineering institutes fared badly in terms of qualitative considerations. The group plans to establish full-fledged technical education campuses and satellite centres in cities including Chennai, Goa, Pune and Jaipur as it sees rapid transformation in Indian education sector.
Speaking on the current state of technical education in the country, JNTU vice chancellor Rameshwar Rao said commercialisation of technology was low at the university level and India should encourage 'mission critical research' approach to facilitate knowledge sharing between the industry and varsities.

Courtesy:

APPLICATION OF NEURAL NETWORK IN DATA MINING By Prof. Sehgal, DCSE,PPIMT

Google's 'Hummingbird' hatches new search formula

 Google has quietly retooled the closely guarded formula running its internet search engine to give better answers to the increasingly complex questions posed by web surfers.

The overhaul came as part of an update called "Hummingbird" that Google has gradually rolled out in the past month without disclosing the modifications.

The changes could have a major impact on traffic to websites.Hummingbird represents the most dramatic alteration to Google's search engine since it revised the way it indexes websites three years ago as part of a redesign called "Caffeine," according to Amit Singhal, a senior vice president for the company. He estimates that the redesign will affect the analysis of about 90 per cent of the search requests that Google gets.

Any reshuffling of Google's search rankings can have sweeping ramifications because they steer so much of the internet's traffic. Google fields about two of out every three search requests in the US and handles an even larger volume in some parts of Europe. The changes could also drive up the price of Google ads tied to search requests if websites whose rankings are demoted under the new system feel they have to buy the marketing messages to attract traffic.

The search ads and other commercial pitches related to web content account for most of Google's revenue, which is expected to approach $60 billion this year.

Google disclosed the existence of the new search formula on Thursday at an event held in the Menlo Park, California, garage where CEO Larry Page and fellow co-founder Sergey Brin started the company 15 years ago.

Google celebrates its birthday on September 27 each year, even though the company was incorporated a few weeks earlier. The company is now based in Mountain View, California, at a sprawling complex located about seven miles from the 1,900-square-foot home where Page and Brin paid $1,700 per month to rent the garage and a bedroom. The co-founders' landlord was Susan Wojcicki, who is now a top Google executive and Brin's sister-in-law.

Wojcicki sold the home to Google in 2006 and it is now maintained as a monument to the company's humble beginnings.

Google's renovations to its search engine haven't triggered widespread complaints from other websites yet, suggesting that the revisions haven't resulted in a radical reshuffling in how websites rank in the recommendations. The Caffeine update spurred a loud outcry because it explicitly sought to weed out websites that tried to trick Google's search engine into believing their content was related to common search requests. After Caffeine kicked in, hundreds of websites that consistently won a coveted spot near the top of Google's search results had been relegated to the back pages or exiled completely.

Hummingbird is primarily aimed at giving Google's search engine a better grasp at understanding concepts instead of mere words, Singhal said.

The change needed to be done, Singhal said, because people have become so reliant on Google that they now routinely enter lengthy questions into the search box instead of just a few words related to specific topics.

With the advent of smartphones and Google's voice-recognition technology, people also are increasingly submitting search requests in sequences of spoken sentences that resemble an ongoing conversation. That trend also factored into Google's decision to hatch Hummingbird.

Just as Page and Brin set out to do when they started Google in a garage, "we want to keep getting better at helping you make the most of your life," Singhal said.

Besides Hummingbird, Google also announced a few other updates to existing search features aimed at providing information more concisely so people won't need to navigate to another website. These changes are part of Google's effort to adapt to the smaller screens of smartphones that aren't well suited for hopscotching across the Internet.

The additions primarily affect Google's "Knowledge Graph," an encyclopedia-like box that increasingly appears at the top or alongside the search results, and Google Now, a virtual assistant that tailors key information suited to each user's habits, interest and location.

Besides providing informational snapshots of famous people and landmarks, the Knowledge Graph is now capable of comparing the attributes of two different things, such as olive oil and coconut oil. It will also be possible to ask the Knowledge Graph to sort through certain types of information, such as the creative evolution of various artists.

An upcoming update to Google's search application for devices running Apple's mobile operating system will ensure notifications about personal appointments and errand reminders are also delivered on a smartphones or tablets running on Google's competing Android software. Google Now also will start flagging new developments and information about famous people that have previously piqued a user's interest.

Courtesy: TOI

Samsung Curved Screen Smartphone To Launch In October - That's The Next Hardware Innovation

Samsung Electronics Co. Ltd. is all set to launch a new smartphone featuring a curved display screen in the next month. In October 2013, South Korea is going to witness the unveiling of the next set of hardware innovation coming from the hands of the world's top handset maker. At CE, for the past one year, we have been frequently covering research news about bendable screens and foldable displays. So, this hasn't been a surprise for the tech town. Since the fall of 2012, we have been seeing prototypes of the foldable and stretchy screens from the Samsung Display Co. that are made of plastic instead of glass. Famous for its AMOLED screens, Samsung had made a choice of OLEDs here again instead of Plasma or LCD because they can be made flexible and transparent.

So, the news of a smartphone featuring these foldable screens came to light when Samsung's mobile business head of strategic marketing D.J. Lee said, "We plan to introduce a smartphone with a curved display in South Korea in October," at an event launching the Galaxy Note 3 smartphone in Seoul. The last time we heard about Samsung's handheld flexible displays was back in CES in January, where a 5.5-inch prototype device named Youm was revealed.

 ​

In fact, we all know that curved display is already commercially available in large-screen televisions. Samsung and LG Electronics Inc have started selling curved OLED TV sets this year priced at about $9,000. There is not much information about the features or specs of this new Samsung handset so far.

But if the curved screens aren't very impressive, you should be reading about something called the 'Morphees'. Developed by Scientists from Bristol University, the Morphees are the devices that can change their shape as required. Yeah, so, not just bend, we may now have devices that can alter their form altogether to say make a game easier to control or make the screen easily hidden when entering passwords or secure keys. Bristol's scientists have successfully developed 6 different prototypes using dielectric electro-active polymers (DEAPs), shape memory alloys (SMAs) and other wood-like materials. These 6 prototypes are being tested to see which one is safest to use and consumes least electricity.

What do you think about Samsung's move to bring a curved display smartphone? Would there be a solution that lets these tech giants mass produce the parts cheaply and come up with display panels that can be as thin as a sheet and highly heat resistant? Time will tell.

Courtesy:'Engineering & Technology News'