This can't be used for assymetric encryption. The reason you can still see files and filenames on normally encrypted drives is because your OS holds the encryption key AND decryption key in memory (they're actually the same because it's using symmetric encryption). The problem with the assymetric case is that you no longer have the decryption key, so if you encrypt a filename, you don't get to refer to the file anymore, of course unless (as another user commented) you encrypt the filename you're using to reference the file every time you reference the file, which isn't a terrible idea.

You could do that, but it'd be quite inefficient.

Firstly, let's assume that directories aren't encrypted. Otherwise this would be a real PITA - just to locate /foo/bar/baz.txt you'd have to decrypt each component of 001001/011101/110101.encrypted separately.

More importantly, the decrypting software has no way to encrypt things, only decrypt them. So to read 'secret.txt' you can't just encrypt 'secret.txt' to '111000.encrypted'. Instead, you have to iterate through the entire directory listing and decrypt every single filename, until you find one that decrypts to 'secret.txt'.

Obviously this gets pretty bad with even moderately-sized directories. I assume this is why the project doesn't encrypt filenames.