Question for US Rules committee on AH capability within LX NAV computers?

Hi Sean and everyone,

Interestingly, LXNAV has just announced new firmware version 2.8 for the
LX8000, LX8080 and LX9000. I don't think the details are on their web site
yet. In addition to many cool new features, they announced a new
"Competition Mode" for customers using an AHRS. It makes it possible to
switch off the AHRS for the entire contest period. The screen capture in
the PDF file shows a dialog box appearing on the screen showing "AHRS will
be switched OFF for 14 days! Do you really wish to do that?". This implies
that the AHRS is completely disabled and can't be re-enabled for the 14
days.

I imagine that the U.S. Rules Committee will need to approve the new
feature. I don't know whether or not LXNAV has approached the U.S. Rules
Committee in regard to this new feature yet.

It is very easy to remove the AHRS for the entire contest period anyway, but
this new feature would make it so that a pilot couldn't sneak the AHRS back
into the glider during the contest.

I have just installed an LX9000 and AHRS in our DG-1000S. I plan to fly in
a U.S. contest in 2013. If necessary I plan to completely remove the AHRS
from the glider for the duration of the contest. But, I must admit, it
really makes me very, very unhappy/angry that I must remove the AHRS from
the glider, or disable it, or both. I would never use it to cheat. I will
already be agreeing to fly by the rules. It just bugs me that I must
disable this cool and fun high-tech feature because the rules committee
(which I highly respect and appreciate) is worried that pilots would use an
AHRS-like feature to fly up into clouds (which would be unsafe and
cheating).

Best Regards,

Paul Remde

"Sean Fidler" wrote in message
news:11592598.2199.1333289256635.JavaMail.geo-discussion-forums@yneo2...
http://www.youtube.com/watch?v=8wR4a...e_gdata_player

Please endure the music and watch this video, paying particular attention to
2:00 to 2:25 into the short video.

As was often argued with other PNA bases systems recently...why would these
well known soaring manufactures offer instruments which allow precise flight
without reference to the ground? Please comment.

Have these companies been approached by the USRC in the same manner as
Butterfly Nav, LK8000 and XC Soar in terms of providing versions of there
software that is assured of not being usable in contests?

Perry is a few short weeks away and alot of folks may have LXNAV systems in
there cockpits. Certainly a few do. The World Championships will
undoubtedly by full of them.

What is the status of LXNAV 8000, 8080 & 9000 Flight computers in US
contests? Clearly they possess the capability of providing AH functionality
to their pilots, easily.

Sean
F2

Paul Remde wrote:
This implies that the AHRS is completely disabled and can't be
re-enabled for the 14 days.

What if I publish a proof-of-concept patch that adds a horizon to
LX8000 and others, circumventing this switch?

I think I can assemble one for LX8000/9000 (from LXNav) and the
upcoming LX Zeus (from LX Navigation) in a matter of a few days. It
will not be detectable without special equipment. And it will work
without the new AHRS hardware.

(Pilots interested in such an exploit may send me a private message)

If mainline XCSoar gets banned, I will demonstrate that most other
products must be banned, too. Better keep an old first-generation
electronic vario at hand when you attend a contest, to avoid surprises
;-)

I have already written a patch for LK8000 that pretends to be
"LKCOMPETITION" but doesn't actually disable the horizon:

http://git.xcsoar.org/cgit/max/lk800...5859495c5818d2

Given the existence of this patch, contest organizers cannot be sure
whether a pilot's PNA runs an approved LK8000 version or a fake
full-featured version with my patch.

I'm not trying to support cheaters, I just want to make clear that
banning new technology is not a useful measure to prevent cheating.

Max

This statement that you have written a "patch" disabling LK8000 competition
mode is quite untrue.
You are only enabling back the TRI.
On our website we clearly state:

THE ONLY APPROVED AND GRANTED TO BE COMPLIANT VERSIONS FOR COMPETITIONS ARE
DOWNLOADABLE FROM THE OFFICIAL RELEASE AUTHORITY OF THIS SOFTWARE, WHICH IS
lk8000.it .

DOWNLOADING THE SOFTWARE FROM ANY OTHER SOURCE DOES NOT - DOES NOT - GRANT
ANY KIND OF COMPLIANCY.

THE CRC/MD5 CHECKSUM FOR THE EXECUTABLES MUST MATCH THOSE OF THE EXECUTABLES
RELEASED BY THE SOFTWARE AUTHORITY.

This is also required by the US RC, and I believe it is a good approach.
In fact, your faked version will not pass the CRC MD5 check, and the user
will be banned as a cheater for the rest of his life.

So your statement
Given the existence of this patch, contest organizers cannot be sure
whether a pilot's PNA runs an approved LK8000 version or a fake
full-featured version with my patch.

is not true. You must do something more than that: fake the CRC MD5
checksum, and make the TRI it fit inside the same number of bytes of the
code.
And by the way, the compiler generating the code for LK8000 has been
recompiled for the purpose, so I doubt you can regenerate the same code.

Too optimistic, I guess.
paolo



"Max Kellermann" ha scritto nel messaggio
...
Paul Remde wrote:
This implies that the AHRS is completely disabled and can't be
re-enabled for the 14 days.

What if I publish a proof-of-concept patch that adds a horizon to
LX8000 and others, circumventing this switch?

I think I can assemble one for LX8000/9000 (from LXNav) and the
upcoming LX Zeus (from LX Navigation) in a matter of a few days. It
will not be detectable without special equipment. And it will work
without the new AHRS hardware.

(Pilots interested in such an exploit may send me a private message)

If mainline XCSoar gets banned, I will demonstrate that most other
products must be banned, too. Better keep an old first-generation
electronic vario at hand when you attend a contest, to avoid surprises
;-)

I have already written a patch for LK8000 that pretends to be
"LKCOMPETITION" but doesn't actually disable the horizon:

...

PCool wrote:
is not true. You must do something more than that: fake the CRC MD5
checksum

It seems you do not understand the nature of CRC. "Faking" a CRC is
trivial, and is the most basic property of CRC. Better remove the
mention of CRC from your web site, it's embarassing!

Faking a MD5 checksum is not impossible nowadays, but still harder
than winning a contest. And not required at all for "cheating".

Now you tell me how the contest will verify the MD5 checksum
(practical example, not some theoretical contest organized by some
uber-geek), and I tell you how to get around it easily.

(There are enough catch-all cheats that not even the aforementioned
uber-geek will notice, but I'm curious how you imagine the
verification procedure will work in practice)

and make the TRI it fit inside the same number of bytes of the
code.

Don't be silly. That one is just as trivial as "faking" a CRC.

Max

Thanks, Professor.

"Max Kellermann" ha scritto nel messaggio
...
PCool wrote:
is not true. You must do something more than that: fake the CRC MD5
checksum

It seems you do not understand the nature of CRC. "Faking" a CRC is
trivial, and is the most basic property of CRC. Better remove the
mention of CRC from your web site, it's embarassing!

Faking a MD5 checksum is not impossible nowadays, but still harder
than winning a contest. And not required at all for "cheating".

Now you tell me how the contest will verify the MD5 checksum
(practical example, not some theoretical contest organized by some
uber-geek), and I tell you how to get around it easily.

(There are enough catch-all cheats that not even the aforementioned
uber-geek will notice, but I'm curious how you imagine the
verification procedure will work in practice)

and make the TRI it fit inside the same number of bytes of the
code.

Don't be silly. That one is just as trivial as "faking" a CRC.

Max

By the way,
http://git.xcsoar.org/cgit/master/xc...cpp?id=v6.2.6c
inside xcsoar 6.2 there is really a Horizon, and US RC require you to remove
that code even if unused, like we did.
Even if unused, the Horizon code is included by the Makefile
http://git.xcsoar.org/cgit/master/xc...ile?id=v6.2.6c

So the 6.2 version is not compliant to US RC rules.
Instead of trying to help people cheating, I suggest you release a
competition version of xcsoar too.

regards
paolo




"Max Kellermann" ha scritto nel messaggio
...
Paul Remde wrote:
This implies that the AHRS is completely disabled and can't be
re-enabled for the 14 days.

What if I publish a proof-of-concept patch that adds a horizon to
LX8000 and others, circumventing this switch?

I think I can assemble one for LX8000/9000 (from LXNav) and the
upcoming LX Zeus (from LX Navigation) in a matter of a few days. It
will not be detectable without special equipment. And it will work
without the new AHRS hardware.

(Pilots interested in such an exploit may send me a private message)

If mainline XCSoar gets banned, I will demonstrate that most other
products must be banned, too. Better keep an old first-generation
electronic vario at hand when you attend a contest, to avoid surprises
;-)

I have already written a patch for LK8000 that pretends to be
"LKCOMPETITION" but doesn't actually disable the horizon:

PCool wrote:
So the 6.2 version is not compliant to US RC rules.
Instead of trying to help people cheating, I suggest you release a
competition version of xcsoar too.

Thanks for the nice suggestion, but I suggest you actually read and
understand the code before drawing (the wrong) conclusions.

Max

I did.
I could read:
This feature of having a backup artificial horizon based on inferred
orientation from GPS and vario data is useful, and reasonably well
tested, but has the issue of potentially invalidating use of XCSoar in
FAI contests due to rule ref Annex A to Section 3 (2010 Edition) 4.1.2
"No instruments permitting pilots to fly without visual reference to
the ground may be carried on board, even if made unserviceable." The
quality of XCSoar's pseudo-AH is arguably good enough that this
violates the rule. We need to seek clarification as to whether this
is the case or not.

And this feature is included in the 6.2, it does not matter if disabled or
enabled.
The US RC is requesting that such code is not inside the executable.



"Max Kellermann" ha scritto nel messaggio
...
PCool wrote:
So the 6.2 version is not compliant to US RC rules.
Instead of trying to help people cheating, I suggest you release a
competition version of xcsoar too.

Thanks for the nice suggestion, but I suggest you actually read and
understand the code before drawing (the wrong) conclusions.

Max

That is obviously wrong. The AH in 6.2 is bugged and will never be drawn even if the code exists to draw it... How can you prove that such code isn't included in WinPilot, SeeYou, Strepla, etc.?!

So you are confirming that the Horizon code is in the 6.2 version.
You say it is bugged, but the code says the contrary:

Quoted from xcsoar code:
This feature of having a backup artificial horizon based on inferred
orientation from GPS and vario data is useful, and reasonably well
tested, but has the issue of potentially invalidating use of XCSoar in
FAI contests due to rule ref Annex A to Section 3 (2010 Edition) 4.1.2

And xcsoar already knew it was forbidden to use it.
US RC are asking you to remove that piece of code.
The 6.2 version is not US RC compliant, all of a sudden.

Let me add that it was not smart nor clever to come here declaring that it
is easy to cheat by adulterating other's software.
The only software proven to be invalid right now is xcsoar in fact, and
there is no need to adulterate it, because it comes out naturally invalid.

Winpilot, SeeYou, Stretpla, LK, LX8000... why are xcsoar developers
concerned only about what others are doing?
You cannot prove that these software have illegal code inside, but now
everyone know by xcsoar's own admission that Xcsoar has it.
Nice move.

paolo





"Tobias Bieniek" ha scritto nel messaggio
news:20728050.2799.1333488993408.JavaMail.geo-discussion-forums@vbex14...
That is obviously wrong. The AH in 6.2 is bugged and will never be drawn
even if the code exists to draw it... How can you prove that such code isn't
included in WinPilot, SeeYou, Strepla, etc.?!