An encrypting function.

[frizzle]

Hi there,

I need an encrypting function, but haven't got a clue where to start.
First a string has to be encrypted with two different encryption keys.
Both output should be anything a-z / A-Z / 0-9 with a fixed length
(e.g. 20 chars).
(Preferably the encryption keys should pick chars from a string i give
them,
to prevent l's and 1's, o's and 0's etc.)

Then they get inputted again ( say $_POST['name'] and $_POST['code'] )
and i have to decrypt them. I know $_POST['name'] should use
decode/encode-key 1,
and $_POST['code'] should use decode/encode-key 2.
Decoded they should be the same again.
(Example below.)

I hope it's kind of clear ...

Greetings frizzle.
-------- EXAMPLE --------

Input : foobar

Output key 1 : klKpUR867Biwr742gsBd
Output key 2 : 9KdfnbDSnd65sgh45hsd

$_POST['name'] : klKpUR867Biwr742gsBd
$_POST['code'] : 9KdfnbDSnd65sgh45hsd

Result : foobar ( $_POST['name'] === $_POST['code'] )

[Peter Fox]

Following on from frizzle's message. . .

Hi there,

I need an encrypting function, but haven't got a clue where to start. Ummm...yes - where to start.

I can't help feeling that you are not using the right method to do what
you're /really/ trying to achieve. If something is getting re-inputted
then why bother? If you want random numbers then you can generate
random strings with rand and md5 functions *and check input against
session vars* or values regenerated from a database seed.

There's an easy way to avoid o0 etc and that's by replacing one with
a distinctive character. NB 5s, 8B,1L,4A - many screens don't tell you.

I have a hunch you're trying too hard, but without a clearer idea of
what you're trying to do can't go further.

First a string has to be encrypted with two different encryption keys.
Both output should be anything a-z / A-Z / 0-9 with a fixed length
(e.g. 20 chars).
(Preferably the encryption keys should pick chars from a string i give
them,
to prevent l's and 1's, o's and 0's etc.)

Then they get inputted again ( say $_POST['name'] and $_POST['code'] )
and i have to decrypt them. I know $_POST['name'] should use
decode/encode-key 1,
and $_POST['code'] should use decode/encode-key 2.
Decoded they should be the same again.
(Example below.)

I hope it's kind of clear ...

Greetings frizzle.
-------- EXAMPLE --------

Input : foobar

Output key 1 : klKpUR867Biwr742gsBd
Output key 2 : 9KdfnbDSnd65sgh45hsd

$_POST['name'] : klKpUR867Biwr742gsBd
$_POST['code'] : 9KdfnbDSnd65sgh45hsd

Result : foobar ( $_POST['name'] === $_POST['code'] )

--
PETER FOX Not the same since the porcelain business went down the pan
pe******@eminent.demon.co.uk.not.this.bit.no.html
2 Tees Close, Witham, Essex.
Gravity beer in Essex <http://www.eminent.demon.co.uk>

[Carl Vondrick]

You may want to look into Mcrypt
(http://us3.php.net/manual/en/ref.mcrypt.php). But, with Peter said,
what are you really try to achieve?

[Iván Sánchez Ortega]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

frizzle wrote:

Hi there,

I need an encrypting function, but haven't got a clue where to start.

Maybe by RTFM?

http://php.net/manual/en/ref.mcrypt.php

- --
- ----------------------------------
Iván Sánchez Ortega -i-punto-sanchez--arroba-mirame-punto-net

http://acm.asoc.fi.upm.es/~mr/
Proudly running Debian Linux with 2.6.12-1-686 kernel, KDE3.5.0, and PHP
5.1.2-1 generating this signature.
Uptime: 01:22:27 up 4:11, 1 user, load average: 0.57, 0.31, 0.18

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Version: GnuPG v1.4.2 (GNU/Linux)

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AscAJ7+AFeXveYKrlY+iNOo=
=7Y0o
-----END PGP SIGNATURE-----

[Chung Leong]

http://pear.php.net/package/Crypt_Blowfish

[frizzle]

Carl Vondrick wrote:

You may want to look into Mcrypt
(http://us3.php.net/manual/en/ref.mcrypt.php). But, with Peter said,
what are you really try to achieve?

What i'm trying to do is build a way of security that a human is
submitting a form.
I know there are ways out there already, but i also have other purposes
in mind.

Example:

Image random generated according to key 1:

image.php?txt=kjGKUGFfas8gkjafKfasdf

The image is a php file, getting $_GET['txt'], decrypt it according
key 1, and encrypt it according to key 2. The second encrypting
becomes visible in the actual image.

I have a have a hidden form field with the value of key 1, and the
visitor has to insert the text from the image / key 2 into a form
field.

Then after posting i compare the decrypted hidden formfield's value
against the user submitted value ( / image's value). if they match,
the user read the image, and is human ...

It might sound stupid, sloppy or whatever, but i'm just trying to
achieve my goal.

Thanks.

[Jim Michaels]

"frizzle" <ph********@gmail.com> wrote in message
news:11**********************@z14g2000cwz.googlegr oups.com...

Carl Vondrick wrote:

You may want to look into Mcrypt
(http://us3.php.net/manual/en/ref.mcrypt.php). But, with Peter said,
what are you really try to achieve?
What i'm trying to do is build a way of security that a human is
submitting a form.
I know there are ways out there already, but i also have other purposes
in mind.

Example:

Image random generated according to key 1:

image.php?txt=kjGKUGFfas8gkjafKfasdf

The image is a php file, getting $_GET['txt'], decrypt it according
key 1, and encrypt it according to key 2. The second encrypting
becomes visible in the actual image.

I have a have a hidden form field with the value of key 1, and the
visitor has to insert the text from the image / key 2 into a form
field.

Then after posting i compare the decrypted hidden formfield's value
against the user submitted value ( / image's value). if they match,
the user read the image, and is human ...

Not sure, but sounds like a CAPTCHA. They can be OCR'd
(http://www.ocr-research.org.ua/ ) from what I found in an earlier post.

It might sound stupid, sloppy or whatever, but i'm just trying to
achieve my goal.

Thanks.

[frizzle]

Thanks, indeed that's what i meant.
Apparently it's a weaker system then i imagined.
I guess i'll have to find another alternative again ... :(

Greetings Frizzle.
Jim Michaels wrote:

"frizzle" <ph********@gmail.com> wrote in message
news:11**********************@z14g2000cwz.googlegr oups.com...

Carl Vondrick wrote:

You may want to look into Mcrypt
(http://us3.php.net/manual/en/ref.mcrypt.php). But, with Peter said,
what are you really try to achieve?

What i'm trying to do is build a way of security that a human is
submitting a form.
I know there are ways out there already, but i also have other purposes
in mind.

Example:

Image random generated according to key 1:

image.php?txt=kjGKUGFfas8gkjafKfasdf

The image is a php file, getting $_GET['txt'], decrypt it according
key 1, and encrypt it according to key 2. The second encrypting
becomes visible in the actual image.

I have a have a hidden form field with the value of key 1, and the
visitor has to insert the text from the image / key 2 into a form
field.

Then after posting i compare the decrypted hidden formfield's value
against the user submitted value ( / image's value). if they match,
the user read the image, and is human ...

Not sure, but sounds like a CAPTCHA. They can be OCR'd
(http://www.ocr-research.org.ua/ ) from what I found in an earlier post.

It might sound stupid, sloppy or whatever, but i'm just trying to
achieve my goal.

Thanks.

[Jerry Stuckle]

frizzle wrote:

Thanks, indeed that's what i meant.
Apparently it's a weaker system then i imagined.
I guess i'll have to find another alternative again ... :(

Greetings Frizzle.
Jim Michaels wrote:

"frizzle" <ph********@gmail.com> wrote in message
news:11**********************@z14g2000cwz.google groups.com...

Carl Vondrick wrote:

You may want to look into Mcrypt
(http://us3.php.net/manual/en/ref.mcrypt.php). But, with Peter said,
what are you really try to achieve?

What i'm trying to do is build a way of security that a human is
submitting a form.
I know there are ways out there already, but i also have other purposes
in mind.

Example:

Image random generated according to key 1:

image.php?txt=kjGKUGFfas8gkjafKfasdf

The image is a php file, getting $_GET['txt'], decrypt it according
key 1, and encrypt it according to key 2. The second encrypting
becomes visible in the actual image.

I have a have a hidden form field with the value of key 1, and the
visitor has to insert the text from the image / key 2 into a form
field.

Then after posting i compare the decrypted hidden formfield's value
against the user submitted value ( / image's value). if they match,
the user read the image, and is human ...

Not sure, but sounds like a CAPTCHA. They can be OCR'd
(http://www.ocr-research.org.ua/ ) from what I found in an earlier post.

It might sound stupid, sloppy or whatever, but i'm just trying to
achieve my goal.

Thanks.

Why? Is this a high security site?

OCR'ing CAPTCHA images does take time and effort - each one is typically
different. What would be on your site which would require that much effort?

Not to denigrate your site in any form - but the fact is, spammers
et.al. wouldn't bother with 99.99999% of the CAPTCHA images. They'll
just go onto another site.

It's like your front door. Your lock isn't unpickable - it just
requires time and effort on a burglar's part to pick. However, you lock
your door anyway, because it's a deterrent - the burglar will most
likely move on (unless you're storing Fort Knox inside).
--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================

[frizzle]

Jerry Stuckle wrote:

frizzle wrote:

Thanks, indeed that's what i meant.
Apparently it's a weaker system then i imagined.
I guess i'll have to find another alternative again ... :(

Greetings Frizzle.
Jim Michaels wrote:

"frizzle" <ph********@gmail.com> wrote in message
news:11**********************@z14g2000cwz.google groups.com...

Carl Vondrick wrote:

>You may want to look into Mcrypt
>(http://us3.php.net/manual/en/ref.mcrypt.php). But, with Peter said,
>what are you really try to achieve?

What i'm trying to do is build a way of security that a human is
submitting a form.
I know there are ways out there already, but i also have other purposes
in mind.

Example:

Image random generated according to key 1:

image.php?txt=kjGKUGFfas8gkjafKfasdf

The image is a php file, getting $_GET['txt'], decrypt it according
key 1, and encrypt it according to key 2. The second encrypting
becomes visible in the actual image.

I have a have a hidden form field with the value of key 1, and the
visitor has to insert the text from the image / key 2 into a form
field.

Then after posting i compare the decrypted hidden formfield's value
against the user submitted value ( / image's value). if they match,
the user read the image, and is human ...

Not sure, but sounds like a CAPTCHA. They can be OCR'd
(http://www.ocr-research.org.ua/ ) from what I found in an earlier post.
It might sound stupid, sloppy or whatever, but i'm just trying to
achieve my goal.

Thanks.

Why? Is this a high security site?

OCR'ing CAPTCHA images does take time and effort - each one is typically
different. What would be on your site which would require that much effort?

Not to denigrate your site in any form - but the fact is, spammers
et.al. wouldn't bother with 99.99999% of the CAPTCHA images. They'll
just go onto another site.

It's like your front door. Your lock isn't unpickable - it just
requires time and effort on a burglar's part to pick. However, you lock
your door anyway, because it's a deterrent - the burglar will most
likely move on (unless you're storing Fort Knox inside).
--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================

Well you're probably right, but i also still haven't found a 'good'
CAPTCHA method that doesn't rely on sessions.

I'd like to have two inputs: 1 by the user, and one hidden formfield,
each with their own decryption key, and compare those,
but i haven't found a proper encryption / decryption function yet, that
is good, but quite easy to understand (not to break! ;) )

Frizzle.

[Jim Michaels]

"frizzle" <ph********@gmail.com> wrote in message
news:11**********************@o13g2000cwo.googlegr oups.com...

Jerry Stuckle wrote:

frizzle wrote:

> Thanks, indeed that's what i meant.
> Apparently it's a weaker system then i imagined.
> I guess i'll have to find another alternative again ... :(
>
> Greetings Frizzle.
>
>
> Jim Michaels wrote:
>
>>"frizzle" <ph********@gmail.com> wrote in message
>>news:11**********************@z14g2000cwz.google groups.com...
>>
>>>Carl Vondrick wrote:
>>>
>>>>You may want to look into Mcrypt
>>>>(http://us3.php.net/manual/en/ref.mcrypt.php). But, with Peter said,
>>>>what are you really try to achieve?
>>>
>>>What i'm trying to do is build a way of security that a human is
>>>submitting a form.
>>>I know there are ways out there already, but i also have other
>>>purposes
>>>in mind.
>>>
>>>Example:
>>>
>>>Image random generated according to key 1:
>>>
>>> image.php?txt=kjGKUGFfas8gkjafKfasdf
>>>
>>>The image is a php file, getting $_GET['txt'], decrypt it according
>>>key 1, and encrypt it according to key 2. The second encrypting
>>>becomes visible in the actual image.
>>>
>>>I have a have a hidden form field with the value of key 1, and the
>>>visitor has to insert the text from the image / key 2 into a form
>>>field.
>>>
>>>Then after posting i compare the decrypted hidden formfield's value
>>>against the user submitted value ( / image's value). if they match,
>>>the user read the image, and is human ...
>>
>>Not sure, but sounds like a CAPTCHA. They can be OCR'd
>>(http://www.ocr-research.org.ua/ ) from what I found in an earlier
>>post.
>>
>>
>>>It might sound stupid, sloppy or whatever, but i'm just trying to
>>>achieve my goal.
>>>
>>>Thanks.
>>>
>
>
Why? Is this a high security site?

OCR'ing CAPTCHA images does take time and effort - each one is typically
different. What would be on your site which would require that much
effort?

Not to denigrate your site in any form - but the fact is, spammers
et.al. wouldn't bother with 99.99999% of the CAPTCHA images. They'll
just go onto another site.

It's like your front door. Your lock isn't unpickable - it just
requires time and effort on a burglar's part to pick. However, you lock
your door anyway, because it's a deterrent - the burglar will most
likely move on (unless you're storing Fort Knox inside).
--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================

Well you're probably right, but i also still haven't found a 'good'
CAPTCHA method that doesn't rely on sessions.

I'd like to have two inputs: 1 by the user, and one hidden formfield,
each with their own decryption key, and compare those,
but i haven't found a proper encryption / decryption function yet, that
is good, but quite easy to understand (not to break! ;) )

Frizzle.

use MD5 digits as an index into a dictionary array, and use soundex to
compare words in case they mistype, using only a subset of the md5 string?

[Jim Michaels]

"Jerry Stuckle" <js*******@attglobal.net> wrote in message
news:sq********************@comcast.com...

frizzle wrote:

Thanks, indeed that's what i meant.
Apparently it's a weaker system then i imagined.
I guess i'll have to find another alternative again ... :(

Greetings Frizzle.
Jim Michaels wrote:

"frizzle" <ph********@gmail.com> wrote in message
news:11**********************@z14g2000cwz.googl egroups.com...

Carl Vondrick wrote:

>You may want to look into Mcrypt
>(http://us3.php.net/manual/en/ref.mcrypt.php). But, with Peter said,
>what are you really try to achieve?

What i'm trying to do is build a way of security that a human is
submitting a form.
I know there are ways out there already, but i also have other purposes
in mind.

Example:

Image random generated according to key 1:

image.php?txt=kjGKUGFfas8gkjafKfasdf

The image is a php file, getting $_GET['txt'], decrypt it according
key 1, and encrypt it according to key 2. The second encrypting
becomes visible in the actual image.

I have a have a hidden form field with the value of key 1, and the
visitor has to insert the text from the image / key 2 into a form
field.

Then after posting i compare the decrypted hidden formfield's value
against the user submitted value ( / image's value). if they match,
the user read the image, and is human ...

Not sure, but sounds like a CAPTCHA. They can be OCR'd
(http://www.ocr-research.org.ua/ ) from what I found in an earlier post.
It might sound stupid, sloppy or whatever, but i'm just trying to
achieve my goal.

Thanks.

Why? Is this a high security site?

OCR'ing CAPTCHA images does take time and effort - each one is typically
different. What would be on your site which would require that much
effort?

Not to denigrate your site in any form - but the fact is, spammers et.al.
wouldn't bother with 99.99999% of the CAPTCHA images. They'll just go
onto another site.

It's like your front door. Your lock isn't unpickable - it just requires
time and effort on a burglar's part to pick. However, you lock your door
anyway, because it's a deterrent - the burglar will most likely move on
(unless you're storing Fort Knox inside).

I think he's got a point there. I dunno. here's one. Won't guarantee it.
there's better ones out there that mangle fonts.
http://wp-plugins.net/plugin/captcha/
I've looked through the GD source code. it can't mangle fonts. only rotate
them. for that you're probably looking at making a DLL with the bitstream
library or something like that, or relying on windows' truetype font
rendering engine to render a bitmap, which could possibly do the job.


--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================