MD5 ALGORITHM

[Andrew Wade]

I AM TRYING TO IMPLEMENT AN MD5 algorithm on a PIC 18F452.

Any one done this for a pic before? 16 or 18 series.

we use Proton pic basic and assembler.

Andrew

speeder01@btclick.com

 

[JeffM]

I AM TRYING TO IMPLEMENT AN MD5 algorithm on a PIC 18F452.
Andrew Wade (speeder01 @ btclick.com)

I don't think you multi-posted this to quite enough groups:
http://groups-beta.google.com/groups?filter=0&q=MD5&enc_author=tciPbhUAAADO1UGDzMqA7mjWI7krV-C1t4gpnI31jTClftH60ESI_w

Perhaps you should learned a bit about Usenet techniques before
posting:
http://groups-beta.google.com/group/sci.electronics.design/msg/2b8e536c1a0fe846?q=Worst-is-to-MULTI-post-the-same-question-to-several-groups+when-the-question-is-already-answered+learn-to-cross-post

 

[Ben Bradley]

On 11 Aug 2005 12:27:53 -0700, "JeffM" <jeffm_@email.com> wrote:

I AM TRYING TO IMPLEMENT AN MD5 algorithm on a PIC 18F452.
Andrew Wade (speeder01 @ btclick.com)

I don't think you multi-posted this to quite enough groups:
http://groups-beta.google.com/groups?filter=0&q=MD5&enc_author=tciPbhUAAADO1UGDzMqA7mjWI7krV-C1t4gpnI31jTClftH60ESI_w

Perhaps you should learned a bit about Usenet techniques before
posting:

Looks like he's got "techniques" down (he got the task done, the
message is on the groups he decided it should be on), he "just" needs
to learn Netiquette. Unfortunately, it seems many posters read Emily
Postnews and take what she writes literally.

http://groups-beta.google.com/group/sci.electronics.design/msg/2b8e536c1a0fe846?q=Worst-is-to-MULTI-post-the-same-question-to-several-groups+when-the-question-is-already-answered+learn-to-cross-post

-----
http://www.mindspring.com/~benbradley

 

[Andrew Wade]

Sorry chaps.

And of course none of you have ever been struggling on a project with 3 days
to go and desperately looking for help , some where , any where ............
have you

Thanks for your help I hope some young student just starting out in this
game doesn't come across you first and get put off.


Very Best Regards (sorry don't speak Klingon)

"Ben Bradley" <ben_nospam_bradley@frontiernet.net> wrote in message
news:38snf1hppl56peao5chergbjuhsrevlhq5@4ax.com...

On 11 Aug 2005 12:27:53 -0700, "JeffM" <jeffm_@email.com> wrote:

I AM TRYING TO IMPLEMENT AN MD5 algorithm on a PIC 18F452.
Andrew Wade (speeder01 @ btclick.com)

I don't think you multi-posted this to quite enough groups:

http://groups-beta.google.com/groups?filter=0&q=MD5&enc_author=tciPbhUAAADO
1UGDzMqA7mjWI7krV-C1t4gpnI31jTClftH60ESI_w

Perhaps you should learned a bit about Usenet techniques before
posting:

Looks like he's got "techniques" down (he got the task done, the
message is on the groups he decided it should be on), he "just" needs
to learn Netiquette. Unfortunately, it seems many posters read Emily
Postnews and take what she writes literally.


http://groups-beta.google.com/group/sci.electronics.design/msg/2b8e536c1a0f
e846?q=Worst-is-to-MULTI-post-the-same-question-to-several-groups+when-the-q

uestion-is-already-answered+learn-to-cross-post

-----
http://www.mindspring.com/~benbradley

 

[Jim Backus]

On Thu, 11 Aug 2005 15:31:41 UTC, "Andrew Wade"
<speeder01@btclick.com> wrote:

I AM TRYING TO IMPLEMENT AN MD5 algorithm on a PIC 18F452.

http://www.theregister.co.uk/2005/08/11/oz_speed_camera_case/

Apparently it is possible to change data "protected" by MD5 in an
undetectable way.

--
Jim Backus OS/2 user since 1994
bona fide replies to j <dot> backus <the circle thingy> jita <dot>
demon <dot> co <dot> uk

 

[Wot a World]

On Fri, 12 Aug 2005 13:41:44 +0000 (UTC), "Jim Backus"
<jhb@nospam.co.uk> wrote:

On Thu, 11 Aug 2005 15:31:41 UTC, "Andrew Wade"
speeder01@btclick.com> wrote:

I AM TRYING TO IMPLEMENT AN MD5 algorithm on a PIC 18F452.



http://www.theregister.co.uk/2005/08/11/oz_speed_camera_case/

Apparently it is possible to change data "protected" by MD5 in an
undetectable way.

The Chinese research, IIRC was for _selected_ fixed-length pairs of
data blocks that generated identical MD5 hashes and this demonstrated
that a collision is possible and could be found in a reasonable amount
of time. They did _not_ prove that arbitrary data could be arbitrarily
altered and yield the same MD5 hash.

While it is possible, given a message and an MD5 hash, to find another
message that has the same MD5 hash, it is still extremely difficult to
come up with a message that suits the purpose of the attacker and
still have the same hash. (i.e., change a speed readout without adding
all kinds of other filler to alter the message and get it to hash to
the same value)

http://schneier.com/blog/archives/2005/02/cryptanalysis_o.html

http://www.schneier.com/blog/archives/2005/08/the_md5_defense.html

http://www.infosec.sdu.edu.cn/paper/md5-attack.pdf (The Chinese
method)

http://cryptography.hyperlink.cz/md5/MD5_collisions.pdf