How can I encrypt/decrypt arbitrary binary files using Javascript in the browser?

Question

I need to let users load files from their system, encrypt them on-the-fly and upload to the server and do the opposite thing (download files from the server, decrypt on the fly

Answer 1

See https://github.com/meixler/web-browser-based-file-encryption-decryption for an example showing encryption/decryption of arbitrary binary files using Javascript in the web browser, based on the Web Crypto API.