Monday, May 9, 2011

Security in Manet Networks Challenges and Solutions

MANETS recent popularity
  • Self-configuration
  • Self-maintenance
Challenges to security
  • Open network architecture
  • Shared medium
  • Resource constraints
  • Dynamic topology
Goals of MANET Security
  • Protect network connectivity over multi-hop wireless channels
  • Link level solutions + network level solutions
  • Proactive
  • Reactive

Attacks (Network Layer)
  • Routing attacks
  • Attempt to “screw up” the others’ routing tables (remote effect)
  • Forwarding attacks
  • Leave routing tables alone, but change delivery of packets (local effect)
  • Attack dependent on underlying protocol
Attacks (Link Layer)
  • Key attacks
  • WEP
  • DoS attacks - Manipulation of backoff interval
  1. Easy corruption of other’s data
  2. Effects are compounded at higher layers
  3. Solution Outline – A Multi-fence Security Solution
Message Authentication Primitives
  • Message authentication code
  1. One-way hash function based on shared key
  2. Send data + MAC
  3. Verified only by intended receiver
  4. Low computational overhead
  5. Storage requirement
  6. O(n2) keys
  • Digital signature
  1. Public key infrastructure w/ certificates
  2. Encrypt w/ private and decrypt w/ public
  3. Verified by all receivers
  4. High computational overhead
  5. Storage requirement
  6. O(n) keys
  7. Certificate revocation lists
  8. Less resilient to DoS attacks

Secure Routing
  • Usually proactive approach
  • Authenticate source and routing information
  • Based on routing protocols
  • Source-based routing
  • Distance vector routing
  • Link state routing
Secure Source-based Routing
  • Append node ids to dynamically create routing path
  • Goal: Prevent intermediate nodes from altering routing list
  • End-to-end verification of nodes in paths
  • Example protocol (Adriadne) uses hash chaining technique

Secure Distance Vector Routing
  • Advertise global shortest paths to neighbor
  • Based on a distance metric
  • Goal: ensure correct advertisement of distance metric and authentic sender
  • Authenticate aggregation of metric
  • Unclear example in the paper that used hash chain on hop count

Secure Link State Routing
  • Discover neighbors and broadcast that info to everyone
  • Links only added if bidirectional
  • Nodes can collude
  • Goal: authenticate both neighbor discovery and neighbor broadcast
  • Example protocol (SLSP) uses digital signatures
Secure Packet Forwarding
  • Prevention impossible
  • Detection
  • Monitor neighbors
  • Probe path (for failures)
  • Reaction
  • Related to prevention mechanism
  • Global
  • End-host
Open Challenges
  • Larger problem space
  • Thwart attacks but include failures, misconfigurations, and network overload
  • Intrusion toleration
  • Make system robust in the presence of attacks
  • Larger solution space
  • Supplement encryption with other mechanisms (connectivity or route redundancy)
  • Use redundancy on system and protocol levels

High level description of security issues in MANETSFocused on network layer. Especially routing
Proposed “resiliency-oriented” multi-layered solution design – increased fault tolerance in security systems and called for better analysis models.

Cyberwarfare & Terrorism

Tuesday, April 12, 2011


Introduction to Cyberspace - William Gibson in 1984, Cyberspace refer to the virtual world created by communication over the internet.

A crime is an offensive act against society that violates a law and punishable by the government. Below is different between cybercrime, cyberterrorism and cyberwarfare.


Cyberwarfare has been defined by government security expert Richard A. Clarke, in his book Cyber War(May 2010), a "actions by a nation-state to penetrate another nation's computers or network for the purpose of causing damage or diruption. Cyberwarfare in US a military strategy a proactive cyber defense and the use of cyberwarfare as a platform for attack. In China, diplomatic cables highlight US concern that China is using access to Microsoft source code and harvesting the talents of its private sector to boost its offensive and defensive capabilities. However, in Russian state includes allegation of DoS attacks, hackers attacks, dissemination of disinformation over the internet, participation pf tate-sponsored teams in political blogs, internet surveillance using SORM technology and persecution of cyber-disidents. According to Lieutenant Colonel Timothy F. O’Hara, United States Army, Cyber warfare is a very attractive means to accomplish non-kinetic warfare. It has many features that our adversaries would find attractive. Figure 1.0 showed the cyber warfare depth.

Figure 1.0: Cyber warfare Depth


Terrorism is a criminal act that influences an audience beyond the immediate victim. The strategy of terrorists is to commit acts of violence that draws the attention of the local populace, the government, and the world to their cause. The terrorists plan their attack to obtain the greatest publicity, choosing targets that symbolize what they oppose. The effectiveness of the terrorist act lies not in the act itself, but in the public’s or government’s reaction to the act. For example, in 1972 at the Munich Olympics, the Black September Organization killed 11 Israelis. The Israelis were the immediate victims. But the true target was the estimated 1 billion people watching the televised event. However, the primary goal of a cyber terrorist maybe to disrupt, destroy, or “dis-inform” cyberspace. The primary goal might be to use cyberspace to “augment or enhance” some other physical threat or act of terrorism. Cyber terrorism as a method of operation also depends on the group.

According to CYBER WARFARE/CYBER TERRORISM by Lieutenant Colonel Timothy F. O’Hara, cyber terrorism can be conclude that cyber terrorism is not fictional concept. Cyber terrorism is a real and a legitimate threat. Cyber attacks at the low to medium level do occur on a regular basis. However, study clearly indicates that cyber terrorism, as a threat, is not currently and has not been at the level the media pundits would have us believe. A “digital Pearl Harbor” is certainly conceivable, but it is probably unlikely, and the threat diminishes as the level of awareness increases. Correspondingly, the threat of a cyber attack resulting in physical damage is equally unlikely. What is more likely to occur in the future is a steady increase in the number of cyber attacks that we are currently experiencing. These attacks are designed primarily to disrupt digital data and “dis-inform” the public. It is also more likely that the future will see a steady increase in the use of cyberspace to support general terrorist operations. For the same reasons that private businesses and governments derive value added from cyber operations, so will terrorists.

In spite of the events of September 11th we live in an optimistic time. The terrorist group that attacked us on our home soil is on the run. While still dangerous, their over-all effectiveness has most likely been reduced. Although cyberspace is not a risk-free environment, the benefits of private, business, and governmental usage of cyberspace clearly outweigh the risks. The freedom of cyberspace can be maintained, as long as domestic cyber security measures are properly structured so as to minimize damage resulting from intentional cyber attacks

Virtual Private Network - VPN

Wednesday, March 2, 2011

Virtual Private Network Flow

What is VPN

VPN is special type for WAN(Wide Area Network) which achieves to connect without use leased private lines. It uses to establish Internet. Development of VPN is to establish secure and cost effective long distance links between two or more computing networks. VPN has its own set of software programs, protocols and security constructs which make secure connectivity possible. The USP of virtual private computer networks over conventional computer networks lies in the fact that this technology is a significantly low cost alternative. Before we see how VPN works, let us have a look at the types of VPNs that can be set up.

Types of VPN

  1. Remote client access via VPN
  2. Peer to peer VPN (can let two separate local area networks, to be linked together)
  3. Private VPN (private intranet of a company that allows enabling of access control for each user)
How VPN Works

  1. Install VPN client programs on the machines which need remote access
  2. Enable Internet connectivity provided by an ISP, after verification of user name and password.
  3. Access the private network easily use client remote computer.
*Tips: For more secure, established tunnel between VPN server and client.

Benefit of VPN

  1. Substantially easy and inexpensive to set it up
  2. Can provide long distance connectivity, between multiple branches of a company office, by providing secure data transfer and encryption, to enable video conferencing, as well as data transfer.
  3. Reduces the costs involved in maintaining long distance networks and costs of operation.

VPN is a technology that are really cost effectiveness, efficiency and security features of virtual private networks make them attractive and preferred choices over conventional leased line based networks. Because of that, most industry Intranets use VPN technology to establish internal connectivity.

Hope this article has given you a rough idea of how VPN works, offering secure connectivity and resource sharing services.