Computer Security II

by introducing extra hardware, or to use external devices to make a copy of the contents of disks or memory.







Software failures of any kind may cause your system to fail, open your system to penetration or simply make the system so unreliable that it can't be trusted to work properly and efficiently. Even if individual hardware and software components are secure, an entire system can be compromised if the hardware components are connected improperly or if the software isn't installed correctly.







-Media vulnerabilities: Back up media, such as disk packs, tape reels, cartridges, and printouts, can be stolen or can be damaged by dust and stray magnetic and electromagnetic fields.





-Emanation vulnerabilities: All electronic equipment emits electrical and electromagnetic radiation. Electronic eavesdroppers can intercept the signal emanating from computers, networks, and wireless system, and decipher them. The information stored and transmitted by the systems and networks then becomes vulnerable.





-Communication vulnerabilities: If your computer is attached to a network or it can be accessed by a dial-in modem or over the Internet, you greatly increase the risk that someone will penetrate your system. Messages can be intercepted, mis routed and forged. Communications lines connecting computers to each other, or connecting terminals to a central computer, can be tapped or physically damaged. Radio transmissions, the basis of wireless interconnections such as blue tooth are particularly susceptible to interception.





-Human vulnerabilities: The people who administer and use your computer system represent the greatest vulnerability of all..

THREATS

Threats fall into three main categories:

1. 
   
   
   Natural and physical threats: These threats imperil every physical plant and piece of equipment: fires, floods, power failures, and other disasters. You can't always prevent all, but you can find out quickly when one occurs. With fire alarms, temperature gauges, and surge protectors you can minimize the chance that the damage will be severe. You can also backing up critical data off-site and by arranging for the use of a backup system that can be used if an emergency does occur.



2. 
   
   
   Unintentional Threats: Ignorance creates dangers, for example, a user or a system administrator who hasn't been trained properly, who hasn't read the documentation, and who doesn't understand the importance of following proper security procedures. The protection on the password file or on critical system software can solve this problem, also locking out programs and applications that need to access that data



3. 
   
   
   Intentional Threats: These kind of people come in two varieties. outsiders and insiders.

Outsiders: Include a number of different categories:

-Foreign Intelligence agents: these kind of intruders use sophisticated encryption devices and attack installations where classified information is stored.

-Terrorist: There have been attacks on university computers, various DOD networks, and websites, court buildings. The government worries so do airlines, oil companies, and other business that protect information vital to the National interest. Often these attacks coincide with national holidays or protest.

-Criminals: computer crime is lucrative and unlike many other types of crimes for example stole identities, credit card numbers, or social security numbers for sale and use for other people.

-Corporate raiders: memos and informal messages have become more vulnerable than ever to attack by competitors.

-Crackers: These are intruders break down system for the pleasure of break the security and interest in the challenge that represent to defeat the system. These intruders don't do it for monetary or political interest.

80 percent of system penetrations are by fully authorized users who abuse their access privileges to perform unauthorized functions.

Insiders: There are a number of different types of insiders. The fired or disgruntled employee might be trying to steal or looking for revenge. The coerced employee might have been blackmailed or bribed by foreign or corporate enemy agents. The insider might be an operator, a system programmer, or even a casual user who is willing to share a password. The lazy person who doesn't learn how to encrypt the emails, or he doesn't bother to change the password, leave sensitive information in piles on the desk and floor and ignores the paper shredder.

COUNTERMEASURES

There are many different types, but some of them could be:

-Passwords and auditing of security actions, and administrative procedures such as back ups.

-Encrypt the data in mails or other kind of messages.

-Protect your physical computer equipment from damage by natural disasters and intruders.

Use different kind of new technologies to protect your software, EX. Norton programs.

Computer Security i

Hernando Gonzalez







CIS-158 Introduction To Computer Science

Computer Security

What Is Computer Security: Computers became more dispersed, security became more of an issue of preserving data and protecting its validity, also keeping the secrets secret. We can define Computer Security as a branch of technology known as information security as applied to computers. Also we can refer Computer Security to techniques for ensuring that data stored in a computer cannot be read or compromised by any individuals without authorization. The objective of Computer Security includes:

1. 
   
   
   
   Protection of information and property from theft.




2. 
   
   
   
   Corruption or natural disaster.

Computer and network security are built on three pillars, commonly referred to by the C.I.A acronym and means:

1. 
   
   
   
   Confidentiality.




2. 
   
   
   
   Integrity.




3. 
   
   
   
   Availability.

Computer Security and network security are part of a larger undertaking that protects your computer and everything associated with it (terminals, printers, your cabling, and your disk and tapes), but most important your Computer Security protects the information you've stored in your system. That's why Computer Security is often called Information Security.

In some systems or application environments, one aspect of security could be more important than others, your own assessment of what type of security your information requires will influence your choice of which security techniques and products needed to meet those requirements, here few of them:

1. 
   
   
   
   SECRECY AND CONFIDENTIALITY: A secure computer system must not allow information to be disclosed to anyone who is not authorized to access it. Ex. In highly secure government systems, secrecy ensures that users access only information that they are allowed, by the nature of their security clearances, to access. Likewise, in business environments, confidentiality ensures the protection of private information for example (payroll data) as well as sensitive corporate data such as internal memos and competitive strategy documents.




2. 
   
   
   
   ACCURACY, INTEGRITY, AND AUTHENTICITY: a secure computer system must maintain the continuing integrity of the information stored in it. Accuracy or integrity means that the system must not corrupt the information or allow any unauthorized malicious or accidental changes to it. A simple software error changed entries in Bank of New York transactions many years ago, the bank had to borrow $24 billion to cover accounts until the problem was fixed and the mistake cost $5 million in extra interest. Authenticity provides a way to verify the origin of data by determining who entered or sent it, and recording when it was sent and received.

In financial environments, accuracy is usually the most important aspect of security. For example, the confidentiality of funds transfers and other financial transactions is usually less important than the verifiable accuracy of these transactions.

3. AVAILABILITY: A secure computer system must keep information available to its users. The computer system hardware and software keeps working efficiently and the system is able to recover quickly and completely if a disaster occurs.

THREATS TO SECURITY: There are three words that come up in Computer Security issues: vulnerabilities, threats, and countermeasures.

• 
  
  
  
  VULNERABILITY: Is a point where a system is susceptible to attack. Every computer and network is vulnerable to attack. Security policies and products may reduce the probabilities that an attack will actually be able to penetrate your system's defenses, or they may require an intruder to invest so much time and so many resources that it's just not worth it, but also is not there a completely secure system. The typical points of vulnerability in a computer system are:

-Physical vulnerabilities: Your building and equipment rooms are vulnerable. Intruders can break into your server room, just as they can break into your home. Once in, they can sabotage and vandalize your network equipment, and they can steal your back up media and printouts.

Locks, guards, and biometric devices provide an important first defense against break-ins. Burglar alarms and other ordinary types of protection are also effective deterrents.

-Natural vulnerabilities: Computers are very vulnerable to natural disasters and to environmental threats. Disasters such as fire, flood, or earthquakes, lightning, and power loss can wreck your computer and destroy your data.. Dust, humidity, and uneven temperature conditions can also do damage.

In areas where obtaining stable power is a problem, facilities employ back-up generators. These can also help during times of extreme weather. Localized protection can be obtained through installing an uninterruptedly power supply. A properly sized UPS will keep a computer energized long enough to shut down properly and without data loss, and providing power conditioning as well. Dust and other hazards are usually controlled by proper filters on the air conditioning and heating systems

-Hardware and Software vulnerabilities: Some kinds of hardware failures can compromise the security of an entire computer system. If protection features fail, they wreak havoc with your system, and they open security holes. Also is possible to open some "locked systems"