Confidentiality of information prevents the data from being observed by unauthorized personnel. The Confidentiality (or sensitivity) level of data reflects the amount of damage that would occur if the data were made public. Confidentiality is addressed by encryption and access controls.

Integrity refers to the accuracy of information and the prevention of unauthorized modification.The Integrity level of data reflects the amount of damage that would occur if the data were modified in an unauthorized way. Integrity is addressed by digital signatures and access controls.

Availability is the ability to provide information in a timely manner. Generally, availability is addressed by redundant data (backups), redundant connections and redundant systems.

1) They do not benefit financially or militarily.

2) They tend to be disgruntled employees, teenagers, and people with nothing else to do.

3) They are motivated by curiosity.

4) They tend to use well-known attacks.

1)State sponsored or well-funded attackers.

2)Motivated by financial gain, intelligence gathering, cyber-terrorism and Information Warfare.

3) These attackers use unknown techniques.

1) Install the latest patches.

2) Remove unnecessary services.

1) It is expensive.

2) It involves background checks, lie detectors, etc... on users in the system.

3) It reduces the probability of security breaches, but not to zero. 

1) More than one person is required to perform an action within a system.

2) reduces the probability of a security breach, but not to zero.

1) All activities are monitored and recorded.

2) It is a psychological deterent.

3) It is reactive (happens after-the-fact).

1) This is the typical authorization policy used.

2) Permissions are granted only to those who need authorization.

3) "Need to know" is an application of POLP. 

This denies access to unauthorized persons and allows access to authorized users.

1) Intrusion Detection

2) Defense-in-Depth

The management of identification (humand and entity)

Includes:

1) collection of ID information

2) the protection of this information

3) sharing this information

Two-step process

1) Person states their identity with a user ID

2) The person proves that the stated ID is correct (they authenticate the stated ID)

1) By providing a secret known to them (password or PIN)

2) By providing a physical object that is only possessed by them (a token)

3) By providing a physical characteristic that is unique to them (biometrics)

Advantages: 1) Performed in software (no extra expense for tokens or card readers)

2) Common (people are used to it)

3) They can be secure

Disadvantages: 1) They need to be remembered

2) There are several attacks against password authentication

Advantages: 1) Users don't have to remember anything

2) No secret can be observed and reused

Disadvantages: 1) They can be lost or stolen

2) They are physical objects and therefore cost more to implement (cards and card readers)

Advantages: 1) They can't be lost.

2) The user doesn't have to remember anything

3) The user does not have to have anything

Disadvantages: 1) Readers are expensive

2) Biomentric info sent over a network can be intercepted and replayed.

3) Can generate false positives and false negatives

Passwords that are vulnerable to a guessing attack include:

1) Short passwords

2) Common word passwords

3) Passwords that are related to the user (i.e. name of pet, child, etc...)

Describe a password attack known as a

software "Keystroke Logger" attack

Describe a password attack known as a

hardware "Keystroke Logger" attack

The set of passwords of a given length and a given character set. The general formula for the size of password space is:

(size of the character set) ^length

Given a computer can perform 1,000,000 (=10⁶) Brute Force iterations in one second,

how long will it take to Brute Force a 6 character password, giving that there are 3.09 x 10⁸ 6 upper-case letter passwords? 

Since (3.09 x 10⁸)/10⁶ seconds =

3.09 x 10² = 3.09 x 100 seconds (or 5 minutes),

it will take about 5 minutes to try all 6 character upper-case passwords

1) Do not select a dictionary word

2) Use a long password

3) Upper and lower-case letters

4) Digits

5) Special characters (i.e. !$&) 

Discretionary Access Control-An ACL (Access Control List) lists users or user groups and their associated permissions for an object. "Bob (grant, read, write), Student Group (read), Carol (read, write)

One list per object (list identifies users and their permissions)

Discretionary Control List-A C-List lists names of files and directories and the corresponding permissions for the files and directories for that user. "report.xls (grant, read, write), Schedule.doc (read), video-edit.exe (execute)." 

One list per user (list identifies objects and their permissions) 

Pros-Convenient, can assign groups of users

Cons- implementation can be confusing, for example, inherited rights can allow a user to create a file, but not allow them to delete it 

Pros- 1)provide a fine level of granularity for access control

2) could potentially limit the effects of a trojan horse

Cons- 1) Lists can get very large

2) users typically need access to other files as well as their own

1) If the labels are modified a user could see data that they are not authorized to see

2) If the clearance level of the user on a system is modified, the user could see information that they are not authorized to see.

3) The mechanism that performs the label comparison must be tamperproof, always work correctly, and be invoked on every access request.

No Read Up

No Write Down

When Blind Writes are not allowed,

A user is not allowed to write up and

the BLP no write down rule does not allow a user to write down. 

Therefore, a user can only write to files that are labeled at the user's current session level.

Rule 1- No write up

Maintains the integrity of the data by preventing a low integrity user from writing dtat that is labeled high

Rule 2- No read down

Prevents a program performing a high integrity task from reading and acting upon low integrity data. 

BLP no-read-up and no-write-down rules constrain the flow of information. Only permit an upward flow of information based on confidentiality.

Biba no-read-down and no-write-up rules constrin the flow of information. Only permit a downward flow of information based on integrity.

1) Resource exhaustion channels

(storage channels)

2) Timing Channels

Complete- means the accesses are always invoked

Isolated- means the protection mechanisms cannot be modified

Verifiable- the system is small and simple that it can be analyzed 

1) Check for inconsistent policies

2) Check for flawed implementation