The internet is dead. Over 50% of internet activity is now dominated by bots. Before I visit my own new website there were nearly a thousand visitors already, and tens of daily attacks since. If corporate capitalists owning the media and our taxes don’t get our data with consent, their agents would, having our interests in hearts.
I prefer to share my art in the digital world with the utmost protection. Well that’s not quite possible; the solutions like cryptography where you encrypt a message with one key to unlock it, is against sharing, no one else can see it, but it’s obvious there is a secret in there if one cares to decode it. Steganography, however, fundamentally HIDES the SECRET MESSAGE within an innocent-looking cover message. The first documented story of steganography was one of a king who shaved a slaves head, tattooed a secret message on the scalp. After the hair has grown, the messenger is sent off to the destination with a secret shadowed by hair. And the latest story is my Bachelor’s degree thesis on steganography, translated into this app, Terump.
How Terump protects your pdf files?
Offline, steganography, secret scrambling with SHA-256, watermarking, metadata modification
COVER IMAGE is the visible image
(input jpg, png,…) you will see some extracted data from your cover image.
SECRET IMAGE is the hidden message
(input jpg, png,…) the hidden message must have the same dimension as the cover image, if it is not the app will automatically resize, keeping proportions.
WATERMARK IMAGE is printed on the cover image
(input jpg, png,…) the watermark will be visible in the chosen grid locations (multiple choice).
Private KEY scrambles the secret message bits
Leave empty to avoid encrypting the secret. So everyone can decode the secret without a password. If you are sending a secret message you may generate a key and share the with the receiver by other means than the cover.
Steganography Depth is the number of replacing bits per pixel
steganography works by replacing the Most Significant Bits of the secret pixels (1,2,3,4 out of 8) with the Least Significant Bits of the cover pixels. the LSB carries smallest details of the pixel which are invisible to human eye, in contrast with the MSB which carries most of the information about the pixel, In steganography we swap. the MSB for all secret pixels with the LSB of all cover pixels. RGB photos have 8 bits per pixel per color, hiding another RGB secret with same resolution will make the final output occupy a larger disk space and is increased with noise, making it quite suspicious cover image potentially with a secret. to avoid over sizing the output, use 1024 or 720 limit for the output, and create your secret message as simple and low quality possible.
OUTPUTTED PROTECTED PDF WITH SECRET MESSAGE AND WATERMARKS
secret is embedded in one bit per pixel of the cover, it is invisible to human eye. upto 4 bits
The Decoder extracts LSB (same bit depth as encoder used) and descramble them with the correct SHA-256 key (empty, if no key). watermarks cannot be removed and neither of the secret message nor decoded cover can be saved.