Cryptography-How to hide any files in an image

BlindSide is a cryptographic tool. It is possible to encrypt and hide almost any file in an image and then retrieve it later with blindSide. The larger the bitmap file, the more you can encrypt and hide in it. The original image as well as the encoded image looks similar when viewed by the human eye but when run through BlindSide, the hidden data may be revealed.


Tools required:
blindSide  pasword is  way2h
I uploaded the tool to mediafire so you guys can get it easier.
 
The Files required:
-a graphic in .bmp format (scenery pictures and photographs seem to work better that computer generated images)
-a file to encrypt (audio, application, anything, as long as it’s not too large)
 
To encrypt:
Rub blindside
-Open command prompt in the same directory as where the blindSide application is located.
-Now as example, to encrypt file “myAttacker.bat” into “originalImage.bmp” and save the encrypted file as “leetImage.bmp”, type the following excluding the quotation marks:
“BSIDE -a originalImage.bmp myAttacker.bat leetImage.bmp”
To be super safe, you can also add a password as shown below
“BSIDE -a originalImage.bmp myAttacker.bat leetImage.bmp PASSWORD”
 
To decrypt:
Rub blindside
-Open command prompt in the same directory as where the blindside application is located.
-Now to decrypt the same files as used above:
“BSIDE -x leetImage.bmp”
If you wanted to extract a specific file (e.g. myAttacker.bat) you could use the following:
“BSIDE -x leetImage.bmp myAttacker.bat”
If there exists a password for the encryption, the code below will be used:
“BSIDE -x leetImage.bmp myAttacker.bat PASSWORD”
 
To calculate the amount of data an image may hold:
“BSIDE -c originalImage.bmp”


To list files stored within an image: 
“BSIDE -l originalImage.bmp”
 
Why would you want to use blind side?
Well, let’s say I have a key logger, and a batch file to execute the key logger, I can encrypt the two files within an image file, use some binding with windows files functions and there you go. A key logger that runs on a clients machine without the user knowing. A tutorial on how to do this is soon to come if responses to this are good

Cryptography 102: History

Substitution Cipher

One of the most readily known Ciphers is called the substitution cipher, in fact you probably played with one as a kid. However what you didn't know is they are all very badly broken.

A Substitution Cipher is essentially where you create a table where you would say A = C, B = W, C = N all the way to Z = A. This table becomes your key for the cipher, we discussed keys in my earlier lesson. For instance is we had the word "ABBA" and we wanted to encrypt that using our cipher it would come out as "CWWC". To decrypt it we would just use the key in reverse.

Caesar Cipher

Back in the days of Rome when Caesar wanted to send secret messages to people he would use something he developed called the Caesar Cipher. This cipher essentially involves a shift in the letters. For example your Caesar Cipher may be a shift of 3, A = D, B = E, C = F... Y = B, Z = C.

In short this shifts all of the letters values over by 3.

Again we we had a message of "Hello" it would become, "Khoor". We do this by again shifting the letters by 3. They key in this case would be the shift of 3.

Breaking The Substitution Cipher

The first question to ask is what is the size of the Key Space? In other words how many keys could their possibly be assuming there are 26 letters. The key is simply a permutation of all of the letters, if you are a math student you should know that to calculate this you use something called a Factorial, denoted by 26!.

26! is equal to about roughly 2^88, meaning our key is an 88 bit key. A key of this size is very adequate, in fact we will be going over very secure ciphers in a bit with key spaces no bigger than that. However because of the way the Substitution Cipher works, it is very easy to break.

To break The Substitution Cipher we use letter frequencies, this is essentially using the probability of a letter occurring in the English language to break the Cipher. The most common letter in English text is the letter "e" at 12.7%, followed by "t" at 9.1% and then "a" at 8.1%.

So for example, if you gave me a Cipher Text to decrypt that was encrypted using a substitution cipher and I know the original plain text was English, I can crack it with only the cipher text and probability. I would count the frequency of letters in the cipher text, lets say "t" is the most common letter. I can say that the decrypted version of "t" is "e" with high probability.

We can then continue to do this with more letters as well as letter pairs. Frequent letters pairs like "he", "an", "in", "th" and so forth can help us even more to create the decryption table.

Next think you know your message is completely decrypted using only the cipher text, we call this kind of attack a Cipher Text only Attack. This is the lowest level of attack and if your cipher is susceptible to it, well it sucks

Vigener Cipher

The Vigener Cipher combines two messages to create a new decrypted one.

k = C R Y P T O C R Y P T O C R Y P T
m = W H A T A N I C E D A Y T O D A Y
__________________________________

C = Z Z Z J U C L U D T U N W G C Q S

Here is an example of a Vigener Cipher. Pretend every letter has a numerical value, a=1, b=2, c=3 and so forth. In the vigener cipher we add up these values and create a new message with it. C+W=Z, R+H=Z, Y+A=Z, and so forth.

So the key in this case is the word "Crypto", replicated as many times as needed to fit the message. Again breaking this is very easy, but we must first assume we know the length of the key, in this case 6.

We would break up the cipher text into groups of 6.
ZZZJUC|LUDTUN|WGCQS

Than we look at the first letter of every group. We know that the most common letter is "e" so lets suppose we went and counted all of the first letters and it turned out to be "h". We know that H is most likely the encrypted version of "e" so theoretically if we subtract "E" from "H" we should get the first letter in the key. H-E= C which is the first letter in the key.

You would continue to do this for the second letter, and then third letter until the entire set is done using letter and letter pair frequencies. Lets say for instance that you did not know the length of the key, you would simply start and assume the key is the length of 1, solve for that.When it doesn't work you would then go to a length of 2, and so forth until it is decrypted.

Rotor Machines

Another famous example is the Rotor Machine. In a rotor machine the key changes after a letter is pressed. The key actually rotates. If we had a key that said Z = E, we then hit a number, that key would cycle over and A = E now. You can decrypt these using similar Cipher Text Attacks.

Cryptography 101: Overview

In this course you will learn how cryptographic primitives work, as well as how implement them correctly and securely.

Cryptography is Everywhere

Cryptography is used for secure communication

• Web traffic is secured using HTTPS Cryptography
• Wireless traffic uses an array of protocols such as 802.11 WPA2, GSM, Bluetooth
  

It is used for encrypting files on a disk for secure storage using tools like TrueCrypt and EFS.

DvD and Blu-Ray disks have content protection to protect them from being ripped and duplicated. DvDs are secured with CSS and Blu-Ray AACS. It just so happens that CSS is very broken and we will go over how to crack it in a later lesson.

Secure Communication

Everyday we use applications that talk to servers securely using Cryptographic Protocols. For example, when browsing the web we secure our data using HTTPS which is in fact just a protocol called SSL. The goal of this protocol is to make it so the data traveling across the network can't be read by an attacker or tampered with.

Secure Socket Layer

Secure Socket Layer (SSL) also known as TLS consists of two parts.

The first part is called the handshake protocol where the user and the server establish a shared secret key using public key cryptography (we will go over this later).

The second part is called the record layer in which we use this shared secret key to transmit data securely. Because only the user and the server know the key, an attacker can not read or tamper with the data.

Protecting Files on Disk

As I mentioned before, one of the main uses of cryptography is to secure data on a disk. The user generates a secret key just like in secure communication using SSL, this key in then used to write the files to the disk. When the user wants to read these files they must supply the proper secret key to properly read them. This means if the data is stolen it would be completely unreadable without the key, which we will assume the thief doesn't have.

Basic Cryptography

The fundamental building block of cryptography is called symmetrical encryption.

Basically the two parties communicating share a secret key in which the attacker does not know. They use this key in conjunction with a cipher, a set of encryption and decryption algorithms, to secure their data.

The encryption algorithm takes the original data and the secret key and produces what is called a "cipher text". For example, if the original data is the word "hello" the algorithm may convert that into "lb597z" using the secret key.

The decryption algorithm can than take that cipher text and the secret key and turn it back into the original plain text of "hello".

Types of Keys

Single use keys
A single use key is used to encrypt one message. For example, an encrypted E-Mail would generate a new key for every E-Mail.

Multi use keys
A Multi use key is used to encrypt multiple messages. For example, encrypting many files on a disk at the same time would use the same key for each file.