140 likes | 393 Views
Steganography. Outline. Introduction Definition Types Image steganography Algorithm(LSB) Practical Time Bitmap( Bytearray ) Jpg(Chunks) Conclusion. Introduction - definition . What is Steganography??
E N D
Outline • Introduction • Definition • Types • Image steganography • Algorithm(LSB) • Practical Time • Bitmap(Bytearray) • Jpg(Chunks) • Conclusion
Introduction - definition • What is Steganography?? • Steganography: is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message, a form of security through obscurity. • Origin: Greek • steganos(στεγανός): "covered or protected” • and graphei (γραφή) meaning "writing".
Introduction - definition • Difference between Steganography and Cryptography: • messages do not attract attention to themselves • Plain encrypted text is attractive
Introduction - Types • Audio(MP3) • Images(JPEG, BMP, PNG) • Videos • Usually media files… why ??
Image steganography • Image Steganography: hiding information inside images. Any ideas?
Steganography - Algorithms • Least Significant Bit (LSB) • F5 • Jsteg
Practical time- PNG • Example • Get the key
Practical time - Bitmap Jpg Structure: Chunks Chunks : each of which conveys certain information about the image. Bitmap Structure: • Different headers have info about the image • Pixel array: is a block of 2D array. Rows are the date of the pixels. Columns are the pixels • Padding: When the pixel array is loaded into memory, each row must begin at a memory address that is a multiple of 4 • 24-bit bitmap with Width=1, would have 3 bytes of data per row (blue, green, red) and 1 byte of padding
Practical Time • Get the Key • Imgception • Find the key