The actual encryption of the file is secure, but everything else about the site is insecure. Plus using a free web host to encrypt files with 256 aes is kinda silly. The fact you use md5 for password hashing isn't very secure either.
Edit: The idea of this is nice though. Maybe instead of focusing on encrypting the files, focus on providing a very secure environment to store the files in. Plus sort out the ssl and remove plain text transmission. This could turn into a good site
Edit: The idea of this is nice though. Maybe instead of focusing on encrypting the files, focus on providing a very secure environment to store the files in. Plus sort out the ssl and remove plain text transmission. This could turn into a good site