md5

[Greger]

Hi all,
Im quite comfortable with php but new to encryption, could someone please
highlight when encryption would be a good thing.

Also:is there a reverse of the md5 function? ( in other words in what way is
md5 ( + the others sha...)used?
--

http://www.gregerhaga.net

[Marcin Dobrucki]

Re: md5

Greger wrote:
[color=blue]
> Im quite comfortable with php but new to encryption, could someone please
> highlight when encryption would be a good thing.[/color]

When you have a secret to protect?
[color=blue]
> Also:is there a reverse of the md5 function? ( in other words in what way is
> md5 ( + the others sha...)used?[/color]

Ehh... no. MD5 is a one-way hash (http://en.wikipedia.org/wiki/MD5).
You really ought to have a look at some literature, maybe start here:

http://www.sans.org/rr/

/Marcin

[Alvaro G Vicario]

Re: md5

*** Greger wrote/escribió (Thu, 18 Aug 2005 14:21:42 +0200):[color=blue]
> Im quite comfortable with php but new to encryption, could someone please
> highlight when encryption would be a good thing.
>
> Also:is there a reverse of the md5 function? ( in other words in what way is
> md5 ( + the others sha...)used?[/color]

MD5 is a hash that's normally displayed as a 32 character string. That
means that even the MD5 hash of a 2GB files is 32 byte long: if it was
reversable we would have found the most amazing compression algorithm ;-)

Encryption can be rather complicate. I suggest you first define your needs
and then find solutions for them.

Hashes have several usages:

* Test file integrity
* Password storage (you cannot decrypt passwords, yet you can encrypt the
value provided by user and compare)

--
-- Álvaro G. Vicario - Burgos, Spain
-- http://bits.demogracia.com - Mi sitio sobre programación web
-- Don't e-mail me your questions, post them to the group
--

[zen]

Re: md5

Why not use something like:

http://www.sourceguardian.com/

This will encrypt the php source

regards
nik

http://www.ads4links.com

"Alvaro G Vicario" <alvaro_QUITAR_ REMOVE@telecomp uter.com> wrote in message
news:1332o5jql1 6vl$.2avin6ldpf dw$.dlg@40tude. net...[color=blue]
> *** Greger wrote/escribió (Thu, 18 Aug 2005 14:21:42 +0200):[color=green]
> > Im quite comfortable with php but new to encryption, could someone[/color][/color]
please[color=blue][color=green]
> > highlight when encryption would be a good thing.
> >
> > Also:is there a reverse of the md5 function? ( in other words in what[/color][/color]
way is[color=blue][color=green]
> > md5 ( + the others sha...)used?[/color]
>
> MD5 is a hash that's normally displayed as a 32 character string. That
> means that even the MD5 hash of a 2GB files is 32 byte long: if it was
> reversable we would have found the most amazing compression algorithm ;-)
>
> Encryption can be rather complicate. I suggest you first define your needs
> and then find solutions for them.
>
> Hashes have several usages:
>
> * Test file integrity
> * Password storage (you cannot decrypt passwords, yet you can encrypt the
> value provided by user and compare)
>
> --
> -- Álvaro G. Vicario - Burgos, Spain
> -- http://bits.demogracia.com - Mi sitio sobre programación web
> -- Don't e-mail me your questions, post them to the group
> --[/color]

[Dimitry Rybkin]

Re: md5

No one is talking about ecrypting the php source here...

The question was: how does one ecrypt data... not their source files.


zen wrote:[color=blue]
> Why not use something like:
> http://www.sourceguardian.com/
> This will encrypt the php source
>
> regards
> nik
> http://www.ads4links.com
>
> "Alvaro G Vicario" <alvaro_QUITAR_ REMOVE@telecomp uter.com> wrote in message
> news:1332o5jql1 6vl$.2avin6ldpf dw$.dlg@40tude. net...
>[color=green]
>>*** Greger wrote/escribió (Thu, 18 Aug 2005 14:21:42 +0200):
>>[color=darkred]
>>>Im quite comfortable with php but new to encryption, could someone[/color][/color]
>
> please
>[color=green][color=darkred]
>>>highlight when encryption would be a good thing.
>>>
>>>Also:is there a reverse of the md5 function? ( in other words in what[/color][/color]
>
> way is
>[color=green][color=darkred]
>>>md5 ( + the others sha...)used?[/color]
>>
>>MD5 is a hash that's normally displayed as a 32 character string. That
>>means that even the MD5 hash of a 2GB files is 32 byte long: if it was
>>reversable we would have found the most amazing compression algorithm ;-)
>>
>>Encryption can be rather complicate. I suggest you first define your needs
>>and then find solutions for them.
>>
>>Hashes have several usages:
>>
>>* Test file integrity
>>* Password storage (you cannot decrypt passwords, yet you can encrypt the
>>value provided by user and compare)
>>
>>--
>>-- Álvaro G. Vicario - Burgos, Spain
>>-- http://bits.demogracia.com - Mi sitio sobre programación web
>>-- Don't e-mail me your questions, post them to the group
>>--[/color]
>
>
>[/color]