Planning Network Security

The Need for Computer / Network Security:

Computer / network security includes:

Control of physical accessibility to computers / network
Prevention of accidental data
Erasure, modification, compromise
Detection and prevention of
Intentional internal security breaches
Unauthorized external intrusions (hacking)

All three legs of the triangle must exist for a network intrusion to occur:
Motive
A reason to want to breach your security
Means
The ability
Opportunity
The chance to enter the network
This last item is the administrator’s only chance at controlling events.

Principles of Network Security:
Network security goals are sometimes identified as Confidentiality.
Only the sender and intended recipient should “see” the message Integrity.
Sender and receiver want to make sure that the message is not altered in transit, or afterwords. Authentication
The sender and receiver want to confirm each other’s identity Availability.
Services and resources must be available and accessible.

Understanding Risk Management:
A key principle of security is that no network is completely secure.
Information security deals principally with risk management.
The more important an asset, the more it is exposed to security threats, thus the more resources you must put into securing it.

Understanding Risk Management – 2:
In general, without training, administrators respond to a security threat in one of three ways:
Ignore the threat, or acknowledge it but do nothing to prevent it from occurring.
Address the threat in an ad hoc fashion.
Attempt to completely security all assets to the utmost degree, without regard for usability or manageability
None of these strategies take into account what the actual risk is, and all of them will usually lead to long-term failure.

What are Some Risks?
Eavesdropping
Interception of messages
Hijacking
Taking over the role of a sender or receiver.
Insertion
Of messages into an active connection
Impersonation
Spoofing a source address in a packet or any field in a packet
Denial of service (DOS).
Prevent others from gaining access to resources, usually by overloading system.

Managing Risk:
Once the assets and their corresponding threats have been identified risk management can consist of:
Acceptance
Mitigation
Transference
Avoidance

Accepting Risk:
If you take no proactive measures, you accept the full exposure and consequences of the security threats to an asset.
Should accept risk only as a last resort when no other reasonable alternatives exist, or when the costs are extremely high.
When accepting risk, it is always a good idea to create a contingency plan.
A contingency plan details a set of actions that will be taken after the risk is realized and will lessen the impact of the compromise of loss of the asset.

Mitigating Risk:
The most common method of securing computers and networks is to mitigate security risks.
By taking proactive measures either to reduce an asset’s exposure to threats or reduce the organizations dependency on the asset, you are mitigating the security risk.
A simple example: installing antivirus software.

Transferring Risk:
Transfer security risk to another party has many advantage including:
Economies of scale, such as insurance.
Use of another organization expertise and services.
Example: using a web hosting service.
When undertaking this type of risk transference, the details of the arrangement should be clearly stated in a contract known as a service level agreement (SLA).

Avoiding Risk:
The opposite of accepting risk is to avoid the risk entirely.
To avoid risk, you must remove the source of the threat, exposure to the threat, or your organization reliance on the asset.
Generally, you avoid risk when there are little to no possibilities for mitigating or transferring the risk, or when the consequences of realizing the risk far outweigh the benefits gained from undertaking the risk.
An example can be a military or law enforcement dBase that, if compromised, could put lives at risk.

Implementing Security:
Think of security in terms of granting the least amount of privileges required to carry out the task.
Example: consider the case of a network administrator unwittingly opening an e-mail attachment that launches a virus.
If the administrator is logged on as the domain administrator, the virus will have administrator privileges on all computers in the domain and thus unrestricted access to nearly all data on the network.

Defense in Depth:
Imagine the security of your network as a series of layers.
Each layer you pull away gets you closer to the center, where the critical asset exists.
On your network, defend each layer as though the previous outer layer is ineffective or nonexistent.
The total security of your network will dramatically increase if you defend at all levels and increase the fault tolerance of security.
Example: to protect users from launching an e-mail-borne virus, in addition to antivirus software on the users’ computers, you could use e-mail client software that blocks potentially dangerous file types from being executed, block potentially dangerous attachments according to their file type, and ensures that the user is running under a limited user account.

Reducing the Attack Surface:
An attacker needs to know of only one vulnerability to attack your network successfully, whereas you must pinpoint all you vulnerabilities to defend your network.
The smaller your attack surface, the better chance you have of accounting for all assets and their protection.
Attackers will have fewer targets, and you will have less to monitor and maintain.
Example: to lower the attack surface of individual computers on your network, you can disable services that are not used and remove software that is not necessary.

Addressing Security Objectives:
Controlling Physical Access to
Servers
Networked workstations
Network devices
Cabling plant
Being aware of security considerations with wireless media related to portable computers.
Recognizing the security risk.
Of allowing data to be printed out.
Involving floppy disks, CDs, tapes, other removable media.

Recognizing Network Security threats:
To protect your network, you must consider the following:
Question: from whom or what are you protecting if?
Who: types of network intruders and their motivations.
What: types of network attackers and how they work.
These questions form the basis for performing a threat analysis.
A comprehensive threat analysis should be the product of brainstorming among people who are knowledgeable about the business processes, industry, security, and so on.

Classifying specific Types of Attacks:
Social engineering attacks
DOS attacks
Scanning and spoofing
Source routing and other protocol exploits
SOFTWARE and system exploits
Trojans, Viruses and worms

It is important to understand the types of threats in order to deal with them properly.

Designing a Comprehensive Security Plan:
RFC2196, the Site Security Handbook.
Identify what your are trying to protect.
Determine what you are trying to protect it from.
Determine how likely the anticipated threats are.
Implement measures that will protect your assets in a cost-effective manner.
Review the process continually and make improvements each time a weakness is discovered.

Steps to Creating a Security Plan:
Your security plan will generally consist of three different aspects of protecting your network.
Prevention: the measures that are implemented to keep your information from being modified, destroyed, or compromised.
Detection: the measures that are implemented to recognize when a security breach has occurred or has been attempted, and possibly, the origin of the breach.
Reaction: the measures that are implemented to recover from a security breach to recover lost or altered data, to restore system or network operations, and to prevent future occurrences.

Security Ratings:
The U.S. government provides specifications for the rating of network security implementations in a publication often referred to as the Orange Book, formally called the DOD Trusted Computer System.
Evaluation criteria, or TCSEC.
The Red book, or Trusted Network Interpretation of the TCSEC (TNI) explains how the TCSEC evaluation.
criteria are applied to computer networks.
Canada has security rating systems that work in a similar way.
CTPEC

Security Ratings -2:
To obtain a government contract, companies are often required to obtain a C2 rating.
A C2 rating has several requirements.
That the operating system in use be capable of tracking access to data, including both who accessed it and when it was accessed.
That users’ access to objects be subject to control (access permissions).
That users are uniquely identified on the system (user account name and password).
That security-related events can be tracked and permanently recorded for auditing (audit log).

Ant Colony Optimisation for E-Learning Applications Over a Secure Network

This work was initiated when Paraschool, the French leading e-learning company contacted the INRIA research center to conceive an automatic algorithm that would allow the relatively rigid albeit functional existing Paraschool software to behave differently depending on user specificities. After several brainstorming sessions where neural networks, evolutionary algorithms and other artificially intelligent techniques were considered, it appeared that swarm-like algorithms could be used, thanks to the great number of actual users (more than 10000) and more especially ant-based probabilistic optimisation that could easily be grafted on the existing pedagogical graph constituted by the Paraschool software.

Moreover, Ant Colony systems present the interesting property of exhibiting emergent behaviour that allow individuals to benefit from the dynamic experience acquired by the collectivity, which means, in pedagogic terms that a student could benefit from the pedagogic lessons drawn out of his peers’ successes and failures.

The implementation of these algorithms yields results that go beyond the requirements of the Paraschool company which will soon be experimenting in real size the automatic dynamic optimisation of the pedagogic graph (their set of interconnected lessons and exercises) implemented by their software. This paper successively presents a concise description of human-learning concepts and their software implementation, a short description of the technical implementation of the Ant-Colony based optimisation algorithm and a discussion on the use of various selection operators. A set of experiments is then conducted, showing that erroneous arc probabilities can be automatically corrected by the system.

II. ELEMENTS ON THE PHILOSOPHY OF LEARNING

The main concepts of teaching and learning used nowadays are still very old. The two main currents are Constructivism, that was elaborated by Kant and Behaviourism: a theory that came from Pavlov’s experiments.

A. Constructivism

In 1781, Kant tried to synthesize rationalist and empiricist viewpoints. Kant sees the mind as an active agent, that organizes and coordinates experiences. Along these lines, Piaget states that knowledge is not simply “acquired,” by children bit by bit, but constructed into coherent, robust frameworks called
“knowledge structures.” Children are not passive absorbers of experience and information, but active theory builders. Papert, a mathematician, and one of the early pioneers of Artificial Intelligence (he founded the Artificial Intelligence Laboratory at MIT), worked with Piaget at the University of Geneva

IV. IMPLEMENTATION OF THE ANT COLONY:

ALGORITHMIC OVERVIEW

All nodes (html pages) of the new Paraschool software now contain a new ACO-powered NEXT button that leads the user along an arc chosen by a selection algorithm (see section V), based on the probability associated with the arc. This probability is computed by taking several factors into account in the design of a weighted fitness function described in the next section. These factors are the following and play at both
the individual and collective levels:

A. Pedagogic Weights: W

This pedagogical weight is the main value of each arc. It is implemented as a static (i.e. “global”) variable (W), accessible to all ants. (W) is set by the Paraschool teachers and reflects the relative importance of the arcs that come out of a particular node. In other words, the teachers encourage the students to go toward such or such exercise after such or such lesson by giving the corresponding arc a higher weight. This valuation of the graph describes the pedagogic structure that will be optimized by the ACO algorithm

B. Pheromones: S and F

There are two kinds of pheromones that can be released on arcs to reflect students’ activity:

S: success pheromone.
This floating point value is incremented by ants/students on the adequate incoming arcs when
they are successful in completing the corresponding exercise.

F: failure pheromone.
This last value is S’s counterpart for failure. These pheromones are released not only on the arc that
led the ant to that node but also on previous ones in the ant’s history with decreasing amplitude.

This is meant to reflect the fact that the outcome of a particular node (exercise) is influenced by all the nodes (lessons, exercises) the ant went through before but with an influence that, of course, diminishes with time. For obvious pragmatical reasons, this “back propagation” of pheromone release is limited in scope (atypical value of 4 has been agreed upon). To illustrate this, let us consider an ant that went through nodes A,B,C,D,E,F and that reaches node G. When it validates node G with success, 1 unit of success pheromone is dropped on arc (F,G), 1/2 unit on arc (E,F), 1/3 of a unit on arc (D,E) and 1/4 on arc (C,D). In addition, to allow for dynamic adaptability of these pheromone amounts (S and F), evaporation is performed on a regular basis, usually every day, by reducing S and F in a given proportion _ typically around 0.999.

CONCLUSIONS AND PERSPECTIVE

Paraschool wanted a smart automatic system that could adapt to different users without manual intervention, which would be totally unrealistic to envisage on 10000 students. The ant-based system described in this paper not only offers such automatic features by gradually modifying pedagogic paths suggested by teachers using collective experience and by making the structure individual-specific thanks to variables such as H but also comes up with emergent informations that can be used as a refined auditing tool to help the pedagogical team identify the strengths and weaknesses of the software and pedagogic material.

From a more theoretical standpoint, this work can be seen as a new take on Interactive Evolutionary Computation where the solution to a problem is gradually constructed and modified by multiple interacting entities with different and possibly opposite goals. A creative and robust compromise can be reached that balances all the influences and constraints, which allows all participating entities to benefit from an emergent culture and to enhance their decision making processes accordingly. This suggest a great deal of new and exciting applications in the field of Collective Cognition Modelling and Collective Evolutionary Design.

Secure Networks With Network Antivirus Software

For businesses large and small, so much of the information used is contain on computers, and these computers are often connected through a network to allow all your employees to access the files, documents and information needed to complete their tasks. With the amount of computers connected to one another, and also to the internet, problems can arise. Programs and applications such as viruses, malware, spyware, adware etc can end up on your network. The problems that may arise from having these infected programs and files on your system can result in poorer computer performance, hard drives being wiped, or even an inability to access certain folders. This can cost your company a few hundred dollars to fix, as well as losing you money through lack of productivity.

Just as your home computer should have anti-virus software installed, your business should have that protection and security in place. Network anti-virus software is designed different than that for home computer systems. Home use anti-virus software isn’t good or broad enough to be effective on a network, and is usually only made for use with one computer. Network anti-virus software is especially designed to protect many different computers from attack.

When looking into security your network using the software, there are a few things to consider, such as what your needs as. Looking at the specs of your network before you make a purchase, know how many computers and printers are networked together, the bandwidth speed of your system, the servers you are using and also what operating system you have installed. Your budget will also be a determining factor as well. With this in mind, search through online websites to see what products different companies offer and which are the closest to your requirements.

There is some freeware network anti-virus software available, but these aren’t recommended. Much like the home versions, they don’t do as much as the freeware versions and in the end doesn’t offer the same kind of security features. The paid for software will have a more updated database to work with, as well as offering more options for customizability and functionality. The cost will be yearly, but you will be well protected from any infections that may occur. This security is important due to the amount of important information held within your hard drives, and may pay for itself by preventing any problems.

Take into account the company you are dealing with, and choose one that has a proven track record over the years. Research online to see what users and experts think, as some anti-virus software may slow down your system if it doesn’t have the technical specifications needed (Such as RAM, processor speed etc.). Most anti-virus programs will be available for a free or inexpensive trial. Taking advantage of this offer can help you to make a decision through being able to use the program and finding out for yourself if it is what you require. If you are unhappy with the software, uninstall it and download a different trial version.