Use Any Computer Without Leaving a Trace with Tails



Hear a new tricks of the computer .
 If James Bond logs on to a computer, he doesn't want to leave a bunch of files, cookies, or his IP address out there for someone to find. It might seem extreme, but sometimes it's a good idea to take the same precautions yourself.
In this post, we'll walk through how to use a USB stick or DVD to anonymize, encrypt, and hide everything you do on a computer no matter where you are. When we say "browse without leaving a trace", we truly mean it. Using the Linux-based, live-boot operating system Tails (The Amnesiac Incognito Live System), you can use any computer anywhere without anyone knowing you were ever on it. Tails is a portable operating system with all the security bells and whistles you'll ever need already installed on it. You can install Tails on one of your many dust-gathering USB drives or a DVD. We'll show you how to set up your own portable boot disc in the second section, but let's start by taking a look at what you get with Tails.

What Tails Is and What's Packed Into It

The magic of Tails is that you don't have to do a lick of work: once you create your boot disc you'll have a completely anonymous, totally private operating system preloaded with all the software you (or James Bond) would need. What's packed into it? Let's take a look.

The Software Packed Directly into Tails

Browse Like Bond: Use Any Computer Without Leaving a Trace with Tails
Once you create your Tails boot disc, you'll be ready to reboot your computer into an encrypted and private operating system preloaded with all the software you'll need to browse the web, email, IM, and edit documents. Regardless of whether you choose a DVD or USB nothing you do is left on the computer you booted from

  • Built-in online anonymity: The key feature that's going to appeal to most people is Tails' built-in online anonymity. This comes in the form of the customized web browser Iceweasel built using the anonymous web browsing technology from Tor. The browser also includes popular security extensions like HTTPS Everywhere for secure browsing, Adblock Plus to block ads, and NoScript to block Java and Flash. Other than those features, the web browser works exactly like you'd expect a web browser to work.
  • Built-in encrypted email and chat: Additionally, you also get encrypted and private messaging. Tails includes the Claws email client with OpenPGP for email encryption and the instant messaging client Pidgin with an OTR cryptography tool that encrypts your IM conversations.
  • Built-in file encryption: When boot Tails from a USB drive instead of a DVD, you can save documents to the thumb drive and they're automatically encrypted using an encryption specification called LUKS. (Since the DVD is read-only, you can't save any files—which is its own form of security.)
  • A full suite of editing software: On top your web access being private you also get a full suite of work and creative software. Tails comes preloaded with Openoffice for editing documents, Gimp for editing photos, Audacity for editing sound, and plenty more additional software.
Now let's walk through how to set up a boot disc for yourself.

Step-by-Step Guide to Set Up Your Own Tails DVD or USB Drive

Tails is pretty easy to set up on your own and it doesn't differ much from setting up any other Linux Live CD. However, a few extra steps do exist to verify your download.

Step 1: Download the Necessary Files

You need to download two different files to get started with Tails: an ISO (an image of Tails that is burned to a disc) and a cryptographic signature to verify the ISO image:

  1. Cryptographic Signature (Direct download / Torrent)
The developers behind Tails recommend you verify your Tails ISO to make sure it's an officially released version that hasn't been tampered with. We won't walk through that process here, but they have instructions on their web site for Windows and Mac or Linux.

Step 2: Burn Tails to a CD/DVD

You can find documentation for creating a Tails USB from scratch on each operating system here. Alternately, you can more easily make bootable USB installation of Tails after you boot from a Tails live DVD. For our purposes we're going to burn Tails to a bootable DVD because it's an easier process than creating a USB stick from scratch.





Seminar On Anonymous Communication ppt

Definition of Anonymous Communication
Anonymous communication is a necessary measure to protect the privacy of users, and protect computer systems against traffic analysis. Anonymity systems seeks to build an infrastructure running on top of the existing Internet protocols that allows people to communicate with each other without necessarily revealing their personal network identifiers. The basic idea behind any anonymous system is to provide unlinkability between communicating parties by relaying traffic through a number of intermediate nodes. If the messages are delayed and buffered at these intermediate nodes then they can provide stronger anonymity.
Such message based systems are suitable for high latency anonymous applications such as anonymous email. Such sytems are called Mix based system. Circuit based randomized routing techniques like Onion Routing and TOR are used for providing low latency applications like anonymous web browsing or remote login. All these anonymous systems are used by are used by diverse group of users to protect their identities on the Internet
Introduction of CHAUM’S MIX
It is a concept introduced by David Chaum which is based on public key cryptography that allows an electronic mail system to hide whom a participant communicates with as well as the content of the communication . The basic building block of such a high latency anonymous communication systems is a mix. At a high level ,a mix is a process that accepts encrypted messages as input and groups several messages together into a batch , and then decrypts and
forwards some or all of the messages in the batch.

The principal idea is that messages to be anonymized are relayed through a mix. The mix has a well-known RSA public key, and messages are divided into blocks and encrypted using this key. Upon receiving a message, a mix decrypts all the blocks, strips out the first block that contains the address of the recipient, and appends a block of random bits (the junk) at the end of the message. The length of the junk is chosen to make messages size invariant. The most important property that the decryption and the padding aim to achieve is bitwise unlinkability.
An observer, or an active attacker, should not be able to find the link between the bit pattern of the encoded messages arriving at the mix and the decoded messages departing from the mix. More precisely, a mix first generates a public and private key pair and makes the public component known to clients who wish to relay messages through the mix .We let C = Ex (M) denote encryption of a message M with mix x’s publickey, and also let M = Dx(C) denote decryption of a cipher text C with mix x’s corresponding privatekey. Further ,we let Ax represent the identity or address of mix x (e.g., x’sIPaddress).
Consider a sender , Alice , who wants to anonymously send a message M to a recipient , Bob ,via a single mix x .Then , Alice would compute Ex (Rx , M, AB),where Rx is a string of random bits and AB is Bob’s address . She then sends the resulting cipher text to the mix, which can use its privatekey to retrieve M and AB. Rx is simply discarded, but is included in the encryption to help prevent an adversary from identifying two identical messages encrypted under the same asymmetric key . Also alice could first encrypt Message M using publickey of Bob so that even the mix couldn’t read it. This can be concisely represented as
Ex (Rx , M, AB) → M.
The mix collects messages into a batch until it has received “enough” ,and then forwards each to the destination address extracted from the decrypted input message



Biological Computers seminer ppt


What is Biological computers?
INTRODUCTION Biological Computers
Biological computers have emerged as an interdisciplinary field that draws together molecular biology, chemistry, computer science and mathematics. The highly predictable hybridization chemistry of DNA, the ability to completely control the length and content of oligonucleotides, and the wealth of enzymes available for modification of the DNA, make the use of nucleic acids an attractive candidate for all of these nanoscale applications
A 'DNA computer' has been used for the first time to find the only correct answer from over a million possible solutions to a computational problem. Leonard Adleman of the University of Southern California in the US and colleagues used different strands of DNA to represent the 20 variables in their problem, which could be the most complex task ever solved without a conventional computer. The researchers believe that the complexity of the structure of biological molecules could allow DNA computers to outperform their electronic counterparts in future.
Scientists have previously used DNA computers to crack computational problems with up to nine variables, which involves selecting the correct answer from 512 possible solutions. But now Adleman's team has shown that a similar technique can solve a problem with 20 variables, which has 220 - or 1 048 576 - possible solutions.
Adleman and colleagues chose an 'exponential time' problem, in which each extra variable doubles the amount of computation needed. This is known as an NP-complete problem, and is notoriously difficult to solve for a large number of variables. Other NP-complete problems include the 'travelling salesman' problem - in which a salesman has to find the shortest route between a number of cities - and the calculation of interactions between many atoms or molecules.
Adleman and co-workers expressed their problem as a string of 24 'clauses', each of which specified a certain combination of 'true' and 'false' for three of the 20 variables. The team then assigned two short strands of specially encoded DNA to all 20 variables, representing 'true' and 'false' for each one.
In the experiment, each of the 24 clauses is represented by a gel-filled glass cell. The strands of DNA corresponding to the variables - and their 'true' or 'false' state - in each clause were then placed in the cells.
Each of the possible 1,048,576 solutions were then represented by much longer strands of specially encoded DNA, which Adleman's team added to the first cell. If a long strand had a 'subsequence' that complemented all three short strands, it bound to them. But otherwise it passed through the cell.
To move on to the second clause of the formula, a fresh set of long strands was sent into the second cell, which trapped any long strand with a 'subsequence' complementary to all three of its short strands. This process was repeated until a complete set of long strands had been added to all 24 cells, corresponding to the 24 clauses. The long strands captured in the cells were collected at the end of the experiment, and these represented the solution to the problem.
THE WORLD'S SMALLEST COMPUTER
The world's smallest computer (around a trillion can fit in a drop of water) might one day go on record again as the tiniest medical kit. Made entirely of biological molecules, this computer was successfully programmed to identify - in a test tube - changes in the balance of molecules in the body that indicate the presence of certain cancers, to diagnose the type of cancer, and to react by producing a drug molecule to fight the cancer cells.