Protecting Confidential Information From Unauthorized Access by Hiding It in Digital, Innocuous-Looking Carrier Files

Cyberstegano project started from a simple class idea of sending files safely on internet, because normal email attachments can be copied, changed, or read by wrong person. In early stage, only file encryption was planned, but later it was seen that sending the secret key separately is also risky, so hiding the key inside an image was added. The problem statement is: how to share a file through email in a way that the content stays secret, and the key also does not look like a key. The methodology uses a web application made in Flask, where user login is stored in MongoDB, and upload files are encrypted using AES algorithm. A random image is selected from a folder and the key is stored inside image pixel values, then both encrypted file and that image are sent using SMTP email. Techniques used are AES-CBC encryption, Base64 key formatting, simple image data writing using PIL, file handling with secure filenames, and session based login. In conclusion, the system makes file sharing more private than normal sending, though key-hiding method needs careful handling for different image sizes.