Part 1 - Awareness

I want all users who want to know and learn linux to visit this great tutorial first...
[You must be registered and logged in to see this link.]

Thereafter I will do the fine tuning and recommendations.

I hope, there will be questions .... 

hurray     
thats I want from this forum.this is really a good iniative by Admin.
thanx Admin,thanx ESSPEE.

I have read out many basic linux command and doing practice on them.
I want to ask,to build a derivative of any like based os(like ubuntu),is it necessary to have deep knowledge of programming language?
if yes,then which language is best?

Dear friends,

Its not a big deal to make your own Linux OS.

Few essential things to be cosidered:-
1. What is there inside a CD/DVD of any OS (Linux or Windows)
    - A simple answer is a clone of installed OS in a highly compressed file (.wim format in Windows and .squashfs in Linux)
    - A boot image (its not jpg or png) to make your CD/DVD bootable.
    - Few simple scripts to provide guidelines for extractaction.
    .... thats all.

2. Now, next question - How to clone your running OS (If you do not want to build a brand new Linux OS from scratches)
     - There are many ways....
       (a) Complete backup (It will include existing users, passwords, settings)
       (b) Distributable backup (Users will required to create new user, password)
     - Thereafter, these files are to be placed/converted in ISO image format for easy burning on CD/DVD.

3. Thats all.

There are many tools already existing for this purpose. The most common and simple one is "Remastersys" ([You must be registered and logged in to see this link.]). Its a bash script (like a batch file in Windows) which do all tasks as mentioned above. You can customise it as per your choise (Requires some basic knowledge about Linux filesystem and compression)

I visit your mentioned site,but site is something different from other(like 50$ donation thing that I could not understand).
moreover there is no link to download tool. however there is one link
when I clicked on,it shows me this.

Code:

-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.11 (GNU/Linux)

mQENBE64A5QBCADDDL5IvTFZn3kv0fkUaDNMptvytdPI4CQHwwIkDUkFTMvKuqyH
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amyBXL/RXn5l9h52qrcriR8M7oZotOQojupGu6OGeDb6yaJG9cWP7kxSt42aknbI
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fK1yYVBsnPBljm3lluRkCnvJ1VGi4OT26QNjaQqGy3cjzH4V7nhCcR06bnKZjf7q
qw==
=gAUJ
-----END PGP PUBLIC KEY BLOCK-----

what is this public key?
one more question
As the link is for only precise and quantal version,but I am using ubuntu 13.04 version,mai i able to use this tool?

You can download the installer package (It is called binary package in Linux) here:-

[You must be registered and logged in to see this link.]

you can use Remastersys version for Ubuntu Precise for Ubuntu 12.04 and further release.

Public Key ......

Its a part of Cryptography and asymmetric key encryption method. Public-key encryption uses two different keys at once -- a combination of a private key and a public key.

The private key is known only to your computer, while the public key is given by your computer to any computer that wants to communicate securely with it. To decode an encrypted message, a computer must use the public key, provided by the originating computer, and its own private key. Although a message sent from one computer to another won't be secure since the public key used for encryption is published and available to anyone, anyone who picks it up can't read it without the private key. The key pair is based on prime numbers (numbers that only have divisors of itself and one, such as 2, 3, 5, 7, 11 and so on) of long length. This makes the system extremely secure, because there is essentially an infinite number of prime numbers available, meaning there are nearly infinite possibilities for keys.

The Public and Private key pair comprise of two uniquely related cryptographic keys (basically long random numbers). Below is an example of a Public Key:

3048 0241 00C9 18FA CF8D EB2D EFD5 FD37 89B9 E069 EA97 FC20 5E35 F577 EE31 C4FB C6E4 4811 7D86 BC8F BAFA 362F 922B F01B 2F40 C744 2654 C0DD 2881 D673 CA2B 4003 C266 E2CD CB02 0301 0001

The Public Key is what its name suggests - Public. It is made available to everyone via a publicly accessible repository or directory. On the other hand, the Private Key must remain confidential to its respective owner.

Because the key pair is mathematically related, whatever is encrypted with a Public Key may only be decrypted by its corresponding Private Key and vice versa.

For example, if Bob wants to send sensitive data to Alice, and wants to be sure that only Alice may be able to read it, he will encrypt the data with Alice's Public Key. Only Alice has access to her corresponding Private Key and as a result is the only person with the capability of decrypting the encrypted data back into its original form.

As only Alice has access to her Private Key, it is possible that only Alice can decrypt the encrypted data. Even if someone else gains access to the encrypted data, it will remain confidential as they should not have access to Alice's Private Key.

Public Key Cryptography can therefore achieve Confidentiality. However another important aspect of Public Key Cryptography is its ability to create a Digital Signature.

nice work for linux learning help to espee...........     

A lot of good wished to all, who are appearing for NIELIT exams .....

thanks..............