Steganography and Cryptography - Text in Image

About

Encryption is sometimes not enough to secure you secrets, as your secret is known to be passed the only problem is the key is unknown, but that's only one Wall of protection, a smarter way is to hide your secret in plain sight, How can you do that? I hear you asking, Answer is Steganography, with it, you can Hide your secret after being encrypted in a picture, that would be anywhere on the web, and only you and the receiver would know how to extract this secret.

Overview

This App is straight forward, it works both ways:

• injecting secrets, require
  • Path to an Image
  • Path to output Image with secret hidden in it
  • Secret obviously
  • Password to encrypt the secret to ensure that even if the message is extracted it wouldn't be known without the password
• extracting secrets
  • Path to Image with secret
  • Password to decrypt the extracted secret

Encryption

Exclusive OR (XOR) is a logical operation whose output is only true when its inputs differ. XOR can also be used on data bits where 1 stands for true and 0 stands for false. Below you can find both the XOR truth table (on the left) with the input and output values of the XOR operation and the XOR bitwise operation (on the right).

XOR has an interesting mathematical feature: A XOR B = C and C XOR B = A. If A is the message and B the password, then C is the encrypted message. Using B and C, we can reconstruct A. Below is an example where we use Bytes as a message, a password, and an encrypted message:

Thus, not only the same password can be used for encryption and decryption (symmetric encryption), but also the same simple method. This encryption is very strong if the password is random and has the same size as the message.

Injection Algorithm

I used LSB Technique to Hide The Secret, but I only use the blue channel

The message to hide has the String type and UTF-8 charset. As a result, the message can be in any language. In order to conceal the secret message, I converted The message to ByteArray and Then stored each byte bits in the Image respectively, as in figure below

Then Added three bytes (0,0,3) to denote the end of the message

Disclaimer

Although Steganography is a promising way for securing data, the algorithm used in this program is primitive and can easily be detected via Steganalysis

Screenshots

How to Inject Your secret in an Image

Extracting Secret With Correct Password

Extracting Secret With Wrong Password

Image Before and After Injection

Before

After

Fun Fact You'll see a Japanese Symbol ㊙ When Entering Your Secret Which also Means Secret