understanding encryption options in PA

[Socrates]

My question goes somewhat beyond the functions of PA; but since it directly includes those functions (and it is those functions that prompt this inquiry), I assumed that it is legitimate to ask it here.

The more I read about encryption, the more confused I become. I am not really asking about encryption in general, but about the encryption options within PA (including the soon to be released 2013).

As I recall from earlier posts, Spywolf, you described PAE as an encryption "wrapper." The impression I draw from that language is that the archive itself is not encrypted, but rather it is contained within what is presumably an impenetrable electronic wall which keep snooping eyes and keyboards out.

At the same time, your 7zip and zipx formats include their own encryption options. These appear to be internal to the archive structure. Hence, these engines not only compress the files, but, at the same time, they encrypt the contents of that compressed file.

Correct so far? If not, where I am going off the rails?

If I am correct, then (a) it seems that internal encryption would be better that encryption of the wrapper (since, for lack of a better phrase, it seems the encryption is through and through), and perhaps (b) the strongest encryption would be to have both through and through encryption AND an encrypted wrapper.

Still correct? Or not?

Finally, it seems that if a user employs double encryption [b above], then 1) there is a greater chance for the data to become corrupted, and 2) it will also take longer even for the owner to access to the data (since she will have to decrypt it twice — although I thought I once saw—but no longer see—an option to view archives inside a PAE wrapper transparently).

Why do I ask? I am trying to decide which encryption methods to use? In my reading online (which is not always entirely reliable) I seem to find a consensus that AES 256 (SPECIFICALLY Rijndeal AES 256) is the best, although Serpent 256 clearly has its devoted followers.

Direction? Clues about how to decide?