Computer Security CS140 Flashcards
What questions do we need to ask in order to eva, if a system is secure?
Security in what aspects?
Secrecy,damage prevention
Security from whom? All users or differentiate users
What level of Security
Trade-off between cost and performance
Performance degradation
What is the theoretical approach dependant on in the real word?
Implementation
Deployment
Maintenace
Parties involved
Location
Temptation
What three things should be guaranteed in a secure system?
CIA triangle Confidentiality,integrity and availability
Diff between Worm and Virus?
Worm:
Self-contained program that spreads independently.
Exploits network vulnerabilities to access other computers.
Can rapidly infect multiple systems and networks.
Virus:
Malware that requires a host file or program to attach itself to.
Spreads when infected files are shared or executed.
Can cause damage to data, corrupt files, modify or delete data, or steal information.
Similairuty between worm and virus
Similarity: Malicious Intent
Description: Both worms and viruses are forms of malware designed with malicious intent.
Similarity: Self-Replication
Description: Both worms and viruses have the ability to replicate and create copies of themselves.
Similarity: Payload
Description: Both worms and viruses can carry a payload, which refers to additional malicious actions.
What is a DOS and DDOS attack?
Definition: A DoS attack is a malicious attempt to disrupt the availability of a computer system or network by overwhelming it with a flood of illegitimate requests or excessive traffic.
Goal: The goal of a DoS attack is to exhaust system resources, such as bandwidth, processing power, or memory, rendering the targeted system or network unavailable to legitimate users.
What is a Social Engineering Attack?
Definition: Social engineering attacks involve deceptive tactics to manipulate and exploit human psychology and trust in order to gain unauthorized access to information or systems.
Objective: Social engineering attacks aim to bypass traditional security measures by exploiting human vulnerabilities, such as trust, emotions, or cognitive biases.
Methods: Attackers use various methods, such as impersonation, phishing, baiting, pretexting, or persuasive tactics, to trick individuals into revealing sensitive information or performing actions that benefit the attacker.
How can you analyze a security attack?
Who did it, the Motivation behind the attack,Attack vector (means),what was the damage,can this be prevented in the future.
What is a security Asset?
Anything we value enough so that we want to protect it.Example customer database.
What is a vulnerability?
A flaw in a systems design, implementation, operation, or management that could be exploited to violate the systems security policy.
What is a threat?
A potential for the violation of security when an attacker has both the capability and intent to breach security. Threat=capability x intent.
What is the stride model?
It is a threat evaluation model that has the following
Spoofing-Pretending to be a user
Tampering-Modifying or accessing data
Repudiation-Denying involvement in crime
Information Disclosure-Disclosing info without appropriate permisiion
DoS-Denial of service
Elevation of privilege-Hacker elevating their privilege.
What is a risk
Risk: an expectation of loss expressed as the
probability of an actual attack in which a threat
will exploit a vulnerability with a harmful result.
Risk=prbabiltyx harm which equals threatxvulnerbaityxharm
What is an attack?
An assault on security that derives from a threat
Describe the dread model of risk analysis
Damage - how bad would an attack be?
Reproducibility - how easy is it to reproduce the attack?
Exploitability - how much work it needs to launch the attack?
Affected users - how many people will be affected?
Discoverability - how easy is it to discover the threat?
What is a countermeasure?
Countermeasure: an action that reduces a threat,
vulnerability, harm by eliminating or preventing
the attack or by detecting the attack and reacting
with corrective action.
What are the strats to handle a risk?
RIsk avoidance, Risk prevention, Risk detection, RIsk action
How to do informal risk analysis?
Identify assets,identify vulnerabilities,identify threat.
What is cryptography?
It is about secure communication in the presence of adversaries through encryption and decryption
What is secret key encryption
When the same key is used for encryption and decryption.The key is private as is only known to the communicating parties.
What is public key encryption
Use public key to encrypt msg and use private key to decrypt msg.
How does secret key encrypton work?
Secret key is shared between sender and receiver
Plain text is encrypted using private key and AES
Decrypted using Advanced encryption standard and key.
The encryption algos r public.AES and DES
What is steganography?
Is the practice of embedding confidential data within non-secret data in a way that the presence of the secret data is difficult to detect.It is used to hide the existence of the message.
Why do we need steganography?
We need it because usually encrypted msgs r unreadbale which raises suspicion.Therefore we want to hide the encrypted msg within something that is readable.
