Re: ZIP Encryption

Eugene Mayevski wrote:
There are alternative methods to solving the problem. First of all, you can encrypt the files before packing.
Next, you can pack the files before encryption.

It is completely pointless to compress encrypted files. Encrypted data won't compress (unless of course it is Base64 encoded or similar, but in such case the compression rate will only correspond to the 4-to-3 inflation of the Base64 encoding).

Compress first, then encrypt.


compatibility

IME there are not many scenarios in which both (a) compatibility with existing software is absolutely essential, and (b) pass phrase based encryption really solves a correctly analyzed security problem.

The thing is that pass phrase based encryption requires transmission of a secret pass phrase over a secure channel. If the sender and recipient are able to establish such a secure channel, it is usually perfectly doable to transmit or agree upon which software to use as well.

Most of the time, if it isn't feasible to agree upon which software to use, it is also infeasible to establish a secure channel for pass phrase transmission, which makes pass phrase based encryption completely superfluous.
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