compress and encrypt the file

[Wang Xueyan]

Is there any command can both compress and encrypt the file in HP-UX?

[Karthik S S]

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=243432

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=508689

-Karthik S S

[Mark Grant]

I'm not sure of the point here. If I understand compression and encryption technology correctly (which I may well not), you can not usefully compress random data (Otherwise you could compress compressed files ending up with all files compressable to 1 character). Encrypted files are pretty much random data. Therefore, there doesn't seem much point in compressing an encrypted file.

[Laurent Menase]

# gzip -c vm.gz.cr
^^^^ my passwd

to gunzip:
crypt toto vm

Do not do:
crypt toto vm.cr.gz ,
the gzip has no use there, because of the pseudo randomisation of the crypt.
# ll /stand/vmunix vm.*cr*
-rwxr-xr-x 1 root sys 24779560 Jan 29 08:41 /stand/vmunix
-rw-rw-rw- 1 root sys 24783358 Mar 19 10:36 vm.cr.gz
-rw-rw-rw- 1 root sys 9328259 Mar 19 10:37 vm.gz.cr
#

[Elmar P. Kolkman]

It totally depends on your encryption if compression still has any effect. But mind: you're better off encrypting the compressed data then the other way around... Compression tools might put a 'readable' header on a file...

So: gzip -c input | crypt 'passwd' >output

To unpack again, it's off course:
crypt 'passwd'

input

Mind that you might need to put the path when calling crypt!