entΟy, pronounced entropy, allows you to safely and securely encrypt any kind of file, and disguise it as a working image file.
The file (payload) is first highly compressed, which reduces filesize and increases entropy. Then, it's encrypted using the industry and government standard of AES-256-GCM. Next, it's wrapped in an ultra-robust custom encryption cipher. It's then encased with a super secure HMAC to prevent tampering. The two-layer encrypted file is then hidden within your image file. Finally, the polyglot image file (that contains your encrypted & compressed file) as well as a key file are supplied for you to download.
Steganography software cannot decipher the original file, a cryptology expert cannot break the custom cipher, and AES-256 is quantum-resistant.