Lab 4 : Cryptography Extended

Caesar Cipher

A cipher or cryptosystem is a method for message concealment.
The key provides the means for efficient encipherment (encryption).

Plaintext – message in readable form
Ciphertext – encrypted message

example the plaintext encrypted to get the cipher text in

The term steganography is applied to the activity of hiding the existence of a
message.

Cryptanalysis gets extended to other contexts where the messages are hidden (or suspected to e hidden) in text, pictures, music, etc.

Symmetric (or classic secret-key) cryptology relies on the correspondents agreeing on key information over the key (secure) channel.

Asymmetric (public-key) requires two key steps
- one key for encipherment
- A second key for decipherment

Vigenere Cipher

Explanation
EACH column of this table forms a dictionary of symbols representing thealphabet: thus, in the A column, the symbol is the same as the letterrepresented; in the B column, A is represented by B, B by C, and so on.

To use the table, some word or sentence should be agreed on by twocorrespondents. This may be called the `key-word', or `key-sentence',and should be carried in the memory only.

In sending a message, write the key-word over it, letter for letter,repeating it as often as may be necessary: the letters of the key-wordwill indicate which column is to be used in translating each letter ofthe message, the symbols for which should be written underneath: thencopy out the symbols only, and destroy the first paper. It will now beimpossible for any one, ignorant of the key-word, to decipher the message,even with the help of the table.

RSA algorithm

The RSA algorithm is one of the earliest, yet most versatile public key algorithm

The original intent for this algorithm is for keyestablishment/transfer, signing/verification, data integrity, and encryption/decryption

To honour them, the method was referred to as the RSA Scheme. The system uses a private and a public key. To start two large prime numbers are selected and then multiplied together; n=p*q.

RSA takes advantage of the fact that prime numbers are easy to compute and factoring them is reasonably difficult

Lec 4: Operating System Security

In this chapter learn about operating system security. First the concept of a protection defines that the system component that enforces the access control in an operations system. A protection system consists of a protection state which describes the operations that are permitted in a system protection state operations which describe how the protection state may be changed. from this, we can determine the operations that individual processes perform

second, we identify that the today commercial operating system use protection systems that fail so truly enforce security goals. we defined a mandatory protection system which will enforce security in the face of attack

third, we outline the architecture of an access enforcement mechanism that would be implemented by a protection system. Such enforcement mechanisms can enforce a mandatory protection state correctly if they satisfy the guarantee required of the reference monitoring concept

Finally, we defined requirements for a secure operating system based on a reference monitor and mandatory protection style.

Lab 3: Authentication and Basic Cryptography

Encrypting a File or Folder

To encrypt a file or folder from the GUI, follow these steps:
a. Open Windows Explorer or My Computer.
b. Right-click the file or folder that you'd like to encrypt or unencrypt and select Properties.
c. On the General tab, click the Advanced button.
d. From the Advanced Attributes dialog box, mark (or clear) the Encrypt Contents to Secure Data check box to encrypt (or unencrypt) the file or folder that you selected. Click OK to close the Advanced Attributes dialog box and then click OK for the properties sheet to apply this setting. (When you encrypt a folder, you are prompted to select between applying this setting to the folder only and applying it to the folder, subfolders, and files.)
e. To share access to an encrypted file, click the Details button from the Advanced Attributes dialog box. You cannot share access to encrypted folders.
f. From the Encryption Details dialog box, click the Add button to add more users' EFS certificates to the encrypted file to share access with those users.
g. From the Select User dialog box, click the user whose EFS certificate you want to add for shared access to the encrypted file and click OK. You see only certificates for users who have encrypted a folder or file previously.
h. Click OK for the Encryption Details dialog box.
i. Finally, click OK for the Advanced Attributes dialog box and then click OK for the Properties window

Account Lockout Policy
You can access Group Policy settings by opening the Microsoft Management Console (MMC) and adding the Group Policy snap-in.
The Acount Lockout Policy controls settings related to users attempting to login and entering wrong passwords. While it is possible to set this up so that a person can sit there and try thousands of different passwords in an attempt to find the right one, this is highly unwise and a serious compromise of security. There are three settings for this policy and using them will greatly increase security.
Access the Account Lockout Policy from:
Computer Configuration -> Windows Settings -> Security Settings -> Account Policy -> Account Lockout Policy

The three settings that you can set are: Account Lockout Duration, Account Lockout Threshhold, and Reset Account Lockout After. I recommend setting Account Lockout Threshhold to "5 Invalid Login Attempts". When you do this, it will automatically set the other two settings to "30 Minutes". When you apply these settings, a user will become completely locked out of the system for 30 minutes if they enter the wrong password 5 times.

Password Policy
The Password Policy controls settings related to each user's passwords. It is important to enforce a password policy, because the chances of a user giving out their password (accidently or intentionally) is very high. Thus, requiring them to change their password reasonably often and have it conform to a set of standards that make it very difficult to crack is in your organization's best interests.

Access the Password Policy from:
Computer Configuration -> Windows Settings -> Security Settings -> Account Policies -> Password Policy

There are five settings here that you can set. They are: Enforce Password History, Maximum Password Age, Minimum Password Age, Minimum Password Length, and Password Must Meet Complexity Requirements. I recommend that you enforce a password history that is a minimum of 6. This means that a user must change their password six times before they can reuse a password.

For Maximum Password Age, I recommend between 30 and 40 Days - this forces users to change their password every number of days specified in this setting.

Minimum Password Age is also important, because it requires users to use their password a certain amount of time before changing it. A smart user could figure out your system and change their password six times in a row, thus bypassing the password change and compromising your network. I recommend a Minimum Password Age of 1 day, and preferably 7 days. For Minimum Password Length, most enterprises require a minimum length of 8, or sometimes 12. The longer the password, the harder it is to crack. You should definitely enforce Password Must Meet Complexity Requirements.

Lec 3: Program Security

This chapter has covered development issues in computer security: the kinds and effects of security flaws, and in malicious code, and the techniques that can help to control threats. Malicious code receives a great deal of attention in the media; the colorful terminology certainly draws people to stories about it, and the large numbers of affected systems ensure that major malicious code attacks get very wide visibility. But it is important for us to realize that the seriousness of the threat and the degree of vulnerability should also cause people to pay attention.

The total amount of damage already done is not measurable, but it is certainly large. Many successful attacks go undetected—for now, at least. With the explosive growth in connectivity to massive public networks such as the Internet, the exposure to threats is increasing dramatically. Yet the public continues to increase its reliance on computers and networks, ignoring the obvious danger.

In this chapter, we considered two general classes of security flaws: those that compromise or change data and those that affect computer service. There are essentially three controls on such activities: development controls, operating system controls, and administrative controls. Development controls limit software development activities, making it harder for a developer to create malicious programs. These same controls are effective against inadvertent mistakes made by developers. The operating system provides some degree of control by limiting access to computing system objects.


Finally, administrative controls limit the kinds of actions people can take. These controls are important for more than simply the actions they prohibit. They have significant positive effects that contribute to the overall quality of a system, from the points of view of developer, maintainer, and user. Program controls help produce better software. Operating systems limit access as a way of promoting the safe sharing of information among programs. And administrative controls and standards improve system usability, reusability, and maintainability.

For all of them, the security features are a secondary but important aspect of the controls' goals. Program controls are part of the more general problem of limiting the effect of one user on another. In the next chapter, we consider the role of the operating system in regulating user interaction

Lab 2: The Goals of Information Technology

This Lab discusses resource security using NTFS permissions. It specifically discusses security on files and folders within the NT File System (NFTS). The Lab covers NTFS file and folder permissions, access control lists, using NTFS permissions,

Step 1 : Click on the Start button, then select the "Run" command. This will open a small box with a text field. In this field, type 'cmd' without the quotes and press enter.

Step 2 : At the resulting prompt, type in: chkntfs /d: [Enter]
If the message show “D: is not dirty”. This means that there is no corruption on the drive.

Step 3 : Now that we're in the command console, you'll need to enter in the command that will convert the drives. Make sure you type in the command exactly as it's shown (replace 'X:' with the drive letter you need to convert: CONVERT X: /FS:NTFS [Enter]

Step 4 : Close all Windows and log off


Data Confidentiality.

Use NTFS permissions to specify which users and groups can gain access to files and folders, and what they can do with the contents of the file or folder. NTFS permissions are only available on NTFS volumes. The permissions you assign for folders are different from the permissions you assign for files.
You assign folder permissions to control the access that users have to folders and to the files and subfolders that are contained within the folder.

Step 1 : Select Start >>Programs>>Administrative Tools >> Computer Managment
Step 2 : Choose >>Local User and Groups and double clickon the "user" folder.

Step 3 : Create the New User account by selecting User>>New User. The New User dialog box appears.
Step 4 : Complete these fields in the New User dialog box:
a. In the Username field, enter OpenView.
b. In the Full Name field, enter OpenView Administration.
c. In the Description field, enter Permit operation from OpenView services.
d. In the Password field, enter your password.
e. In the Confirm Password field, re-enter your password
f. Click button [Create]

_______________________________________________________________________

Creating data Confidentiality between 2 user accounts.
Step 1 : Log on to the Windows 2003 server as Administrator.
Step 2 : Create a new folder called Confidentiality.
Step 3 : In F0lder Confidentiality, crate another new folder called User1Folder
Step 4 : Right-click User1Folder >>[Properties] >> open the User1Folder Properties
Step 5 :Right-click the file or folder for which you want to assign permissions, In the Security tab
Step 6: Click on the Advanced Button

Step 7 : To add permissions to user accounts or groups for the folder, click Add

Step 9 : Uncheck the box “Allow inheritable permissions from parent to propagate to this object”.

Step 10 : Click [Copy] to retain the permissions.

Step 11 : Click [Add] and the Select Users, Computers, or Groups.Step
Step 12 :Type User1 and then click [Checks Names] and click OK


Step 13 : click the Allow Full Control box and then click OK for Permission Entry windows, .
Step 14: Remove the other username except Administrator, System and User1 by clicking the username

Step 15 : Click OK and Double-click User1Folder and you should see the content of the folder
Step 16 : All windows and log off close
Step 17 : Log on as User2 and navigate to the User1Folder, try to open this folder
Step 18 : Close all windows and log off.

Assigning Special Permissions

The standard NTFS permissions generally provide all of the access control that you need to secure your resources. However, there are instances in which the standard NTFS permissions do not provide the specific level of access that you may want to assign to users. To create a specific level of access, you can assign NTFS special permissions. This lesson introduces the NTFS special permissions. It then outlines the requirements and procedures for taking ownership of a folder or file.

Special permissions are set on the Permission Entry For dialog box for the file or folder. This dialog box is accessed by selecting Advanced on the Security tab of the Properties dialog box for the file or folder, and then selecting View/Edit for a Permission Entry on the Access Control Setting For dialog box for the file or folder.

Lec 2: Authentication & Basic Cryptography

All people must have authentication for identification allows one party (the verifier) to gain
assurances that the identity of another (the claimant) is as declared, thereby preventing impersonation. The most common technique is by the verifier checking the correctness of a message (possibly in response to an earlier message) which demonstrates that the claimant is in possession of a secret associated by design with the genuine party. Techniques which provide both entity authentication and key establishment are often integrated, Other names: entity authentication, identity verification


Cryptography to increase privacy:

There are two basic methods for data encryption:
- Symmetric key cryptographydata is encrypted and decrypted with the same key. the strength of encryption depends on the size of the key: a key with less than 40 bits is to be considered insecure, while a key with more than 128 bits is fairly unbreakable.the problem is: how get both parties the secret key in the first place

-Public key cryptographypublic key cryptography requires two keys, a secret ("private") key and a well known ("public") key. there are two different scenarios where public key cryptography may be used:
1. Send a secret message that only a particular receiver shall be able to read:the sender encrypt the message with the receiver's public key, only the holder of the corresponding private key can decrypt an read the message.
2. Digital signatures:the author of a document encrypts the text with his private key. anyone who knows the authors public key can decrypt and read the message, this reliably authenticates the author.

Lab 1: Introduction to Virtualization & VMware

Today i would like tho share information about VIRTUALIZATION & VMware. Firtly you should be to know what is the virtualiztion? Virtualization is a proven software technology that is rapidly transforming the IT landscape and fundamentally changing the way that people compute. Virtualization lets you run multiple virtual machines on a single physica machine, sharing the resources of that single computer across multiple environments. Different virtual machines can run different operating systems and multiple applications on the same physical computer

WHAT IS VIRTUAL MACHINE?
A virtual machine (VM) is an environment usually a program or operting system, which does not physically exist but is created within another environment. In this context, a VM is called a "guest" while the environment it runs within is called a "host" while the environment it runs within is called a "host." Virtual machines are often created to execute an instruction set different than that of the host environment


VMware Workstation Installation.

VMware Workstation Can be Downloaded from http://www.vmware.com/download/ws/

1. Double Click on the VMware launcher to start the installation Wizards

2. Click on [Next].

3. Choose Typical setup type
4. Choose the location for VMware Workstation installation, example: C:\Program
Files\WMware\VMware Workstation\, Click on [Next].

5. Configure the shortcuts for the VMware Workstation and click [Next].
6. Click on [Install], this will take several minutes to finish

7. Enter the Serial Number for the VMware workstation.


8. Click [Finish], and restart the Computer.



VMware
VMware Workstation makes it possible for PC user to use Multiple Operating Systems. Concurrently on the Same PC. User can create and run multiple virtual machine on desktop or laptop computer. VMware Workstation let you create a virtual machine that can be installed with different kinds of Operating System. Each virtual machine virtualized a complete set of PC, including Memory, HDD, network connections, peripheral ports and processor.



Creating Disk Image

1. From the home tab click on [New Virtual Machine], to open the virtual machine wizard

2. Click [Next] to continue.
3. Choose the typical configuration, click [Next]
4. Choose the type of OS to be installed on the virtual machine. As the next task the virtual machine will be installed with Windows Server 2003, select [Microsoft Windows] as the guest. In the version list, select Windows Server 2003 Standard Edition. Click [Next]. Refer figure 1.10.

5. Name the virtual machine and specify the location where the disk image for the virtual machine
will be stored in the hard disk. Name the virtual machine as winserv03.

6. For the network type select [Use host-only Networking], this selection will create LAN between the other virtual machine.In order to make the virtual machine connected to the real network select [Use bridged networking]. This setting can be changed once the virtual machine is created. Click[Next]. Refer figure 1.12.


7. Specify the disk capacity of the virtual machine. This option will let user to specify the maximum storage capacity of the virtual machine. In this task set the storage capacity between 2GB to 4GB (Depends on the size of your PC). Select [Allocate disk space now] and click [Finish] to start creating your virtual



8. Once your disk image that holds you virtual machine is created you will see figure 1.14. Click [Close]


Get to know the virtual machine console.

Once the virtual machine is created, the tab will contain the home and summary view of winserv03 virtual machine configuration. Refer figure1.15
.

Installing Windows Server 2003 on virtual machine.

1. Place the Windows Server 2003 installer CD in your cdrom drive

2. From the command menu click on [start the virtual machine] or you can click on the start button on the toolbar, your virtual machine is starting and will be booting from your cdrom drive. Refer figure 1.16 (a)

3. Once the winserv03 booting you will see the familiar windows server 2003 installatio page from this point onward you can follow the windows server 2003 installation step.
4. After the installation process is finish, you will see the windows server 2003 login page.

5. Click on the console to start using the windows server 2003, to get the mouse pointer back to your host desktop, type CTRL + ALT on the keyboard.

6. You can try taking the snapshot of your OS by clicking on the [snapshot] button on the toolbar.If anything happened to your OS you can simply click the [Revert] button and choose your previous state.

7. You can also manage the size of your console screen by click on the [Quick switch] and [Full Screen] view option button on the toolbar.