encryption bloats file

[Robert J. Hansen]

On 6/17/2010 2:16 PM, Scott Lambdin wrote:
> The vender told our trading partner their PGP software bloats the file
> and that is just the way it is.  I do not understand how the encrypted
> file (or the file that contains the encrypted file) can be over twice
> the size of the original, when the senders believe they have used
> compression. 

This is not unheard of.

First, compression only works when the data hasn't already been
compressed.  Many data formats (.jpgs, .pdfs, etc.) incorporate
compression, and so cannot be further reduced.

Second, if the sender is using ASCII armoring for their message, that
will result in an enormous increase in file size.  (On the plus side, it
means the message is a text message, which is more convenient for some
purposes.)

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 5598 bytes
Desc: S/MIME Cryptographic Signature
URL: </pipermail/attachments/20100617/c4a44735/attachment.bin>