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All comments by Richard Willey
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Let me offer an example from my own experience…

Well over 10 years ago, I attempted to get the ACBL's C&C to approve a suggested defense to an Ekrens style 2D where 2D showed a preemptive hand with (4+ Diamonds and 4+ cards in either major).

The defenses that I submitted were based on penalty doubles in direct seat. Chip Martel insisted that any direct seat double needed to be for take out. When I showed him that all of the defenses to this type of method in Europe were based on penalty doubles he the stated that this was too complicated to be played in North America. Shortly thereafter, assumed fit methods that could have 4-4 in the two suits were banned as “purely destructive”.
Aug. 22, 2016
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If we do want to jump into minutia, I think that the defining characteristic of a relay system is the notion of a relay captain and a relay responder.

Relay systems are designed to facilitate an asymmetrical exchange of information.

Relay systems MAY swap who is captain and who is responder
Relay systems MAY transition to using descriptive bids by both players

However, any relay systems must provide SOME sequences in which one player can do all the asking and the other player does all the telling. (And I still believe that you only want these restrictions in place over 1D/1H/1S opening bids)
Aug. 22, 2016
Richard Willey edited this comment Aug. 22, 2016
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After some thought, I think that any definition of “invitational” bid needs to be tied to a bid being descriptive in some.

Tautologically, a game invitational bid needs to offer a good chance of making game against some set of hands that opener has. However, I would extend this such that the invitational bid needs to provide some information about the type of hands that would offer a good chance of game.

For example, a game invitational hand might show a “range”. If opener is stronger than X, opener should be game. Alternatively, a game invitational bid might show shape “If opener has a fitting value opposite suit Y, opener should bid game”.

If this can't be described relatively precisely, then I think that the bid should be described in some other way than “invitational”

I think that I could also be convinced that (by definition) an invitational bid should establish a forcing pass up to the level of 2NT.
Aug. 22, 2016
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I have a question about the notion of a relay system.

It is my impression that the C&C does not object to players using multiple relays after strong club openings and after 1NT opening. However, they don't want players to be able to use relays after 1M openings and 1D openings.

It's probably worthwhile to focus on this type of broad principle before getting bogged down in minutia.
Aug. 22, 2016
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I think that the concept of a “psych” is fundamentally flawed and should be replaced with the concept of a “mixed strategy”. This has the benefit of more precisely aligning the regulatory structure with players actual behavior.

(See also “Psychic control”)
Aug. 22, 2016
Richard Willey edited this comment Aug. 22, 2016
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I do not believe that the expression “Purely Destructive bid” can be objectively defined. I think that this is nothing more than a pejorative and should be dropped from the regulatory system.
Aug. 22, 2016
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> What, specifically, should a potential playing sponsor
> do to “vet” potential teammates?

What's the old saying…

Oh yes. “Caveat emptor”
Aug. 20, 2016
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This keeps getting better and better. The husband of one of my bridge partner's weighed in on this. Here's what he had to say:

“It is worse than you think.

https://en.wikipedia.org/wiki/Linear_congruential_generator#Advantages_and_disadvantages_of_LCGs

Look for that constant… ;) That special, special constant.

Now, google on how to attack the unix rand function. (Unix moved away
from this RNG for a reason.)

The assignment to ”Reverse a random number generator, given it's
outputs.“ is a standard homework assignment.

The ONLY thing that may be wrong with your attack is they may pull in
the time, for each session… that would make your attack as stated
wrong. But, the whole thing is so trivial.. who cares.

The ACBL should be ashamed of this one. It is SO easy to fix, that it
shouldn't be allowed to live.”

BTW, please recall a portion of the discussion yesterday in which I stated that the algorithms used for these sorts of things should be made publicly available as to avoid obvious flaws.

Its been less than 20 hours since the ACBL provided me with a description of their methodology. During that time, folks have demonstrated multiple different attack vectors.
Aug. 20, 2016
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I'd say that the biggest problem is using the same seed to generate 2,000 sets of hands…
Aug. 20, 2016
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FWIW, I expressed my concerns about the system being used to a few folks in the ACBL: I received a polite response from Keith Wells (the ACBL's “Tournament Technical Analyst”) which I have reproduced in full at the close of this post.

If I am reading things correctly, the system is actually much worse than either Nic or I portrayed. From my perspective, there are three points of interest wrt the existing system:

1. The seed length is 2^47
2. The ACBL uses this seed to generate a block of 2,000 sets of hands
3. 16 years ago, folks were able to crack 56 bit DES in roughly 24 hours. (Admittedly, this used dedicated hardware, but between Moore's Law, the relatively short key length, and the glory that is Amazon Web Services…)

In theory, the following should be feasible:

1. Get a set of ACBL hand records.
2. Go home. Brute force the seed
3. Generate the 1,999 hand sets that come after this one and the 1,999 sets that came before it
4. Come the next tournament, plug hand 1 into my Lookup table and extract the remaining hands for this set.

Simply put, re-using a short key for long periods of time is a really bad idea…

Wells states: “With so many of the variables involved in the hand record set creation process kept protected and secure, I doubt anyone will be cracking the security in sufficient time to make use of the data they develop.”

It would be nice if Well's understood that most of the complexity of the system is intended to ensure that the random seed is uniformly distributed across the 2^47 length key space, but don't need to be known to crack the resulting system…

_________________________

Hello, Everyone,

I was following this conversation on the Bridgewinners website with some degree of amusement, as the degree of code cracking necessary to accomplish a read of the hand record set within a three hour period (a typical play session) does not currently exist. Here is the description of the program used by ACBL, provided by the programmer, Jim Lopushinsky. This was published in the September 2011 Bulletin.

"The following is an excerpt from a letter to the editor, with a response by Lopushinsky, published in the September 2011 issue of the ACBL Bridge Bulletin that may help shed some light on the dealing program used by the ACBL.

Bill Clough of Lynchburg VA wrote: “The question is whether the ACBL hands are random. Let’s look at some numbers. From the ACBL’s own web site, we can find that a huge number of deals can be generated as the random seed is 2^47, that is 140,737,488,355,328 or 1.4x10^14 possible deals. The seed is equal to the largest possible number of unique deals that can be generated.
“It is true that the total number of possible deals is closer to 2^96, but there are actually 53,644,737,765,488,792,839,237,440,000 or 5.3644x10^28 possible bridge deals.
“Surfing the web a few years back, I found an article that helped to understand these enormous numbers. If you have one atom of gold for each possible bridge deal, a gold cube could be formed 3.9 feet on a side and weigh 19 tons with a value more than $800 million.
“Doing the same for the ACBL deals, the cube of gold formed would be 1/1500 of an inch and weigh .05 microgram – less then the ink of the dot on an “i” – with a value of 1/5000 of a cent.
“So are the ACBL deals random? Yes, of course, they are random – as random as the generating program can make them.”

This was Lopushinsky’s response:
“The writer is correct as to the number of hands that can be generated from one seed, but the seed is arbitrarily assigned for each set of hands.
“The random number generator uses the linear congruential algorithm and 48-bit integer arithmetic. This will generate 2 to the 47th power different numbers before repeating without any outside influence (140,737,488,355,328 numbers).
“Outside influence occurs in the form of manually dealt hands, starting seed numbers, time of day, etc., to make the number of numbers virtually infinite, and to guarantee that the same hand will not be repeated. Ninety-six bits take part in the operation with the high 48 bits acting as the overflow.
“The operation works as follows: The hand record set number is used as the starting seed. This seed is multiplied by day of the month, current minute, current hour, current second, current day of week and current hundredth of second. This number is then multiplied by a large prime number (5DEECE66D in hexadecimal). Thirteen is then added to this. The lower 48 bits is then saved and used as the seed to generate the next random number. The overflow (48 high bits) is then doubled and multiplied by the range requested (1 - 52) and the overflow from this is used as the random number.”

The computer used to run the ACBL hand record generator is a stand alone desktop computer that is not connected to any network. Since Jim's retirement in May, I have been responsible for maintaining our stock of electronic hand records used by our Tournament Directors.

When we need additional hand records, we generate two thousand sets at a time (72,000 deals). The seed deal is manually entered at the beginning of the process, and is not part of any set subsequently produced. Sets are never reused, and the number of the set is not released publicly until after play. The date and time when the hand record was prepared (we keep a five thousand set buffer) does not leave ACBL Headquarters.

With so many of the variables involved in the hand record set creation process kept protected and secure, I doubt anyone will be cracking the security in sufficient time to make use of the data they develop.

Regards,

Keith Wells
ACBL Tournament Technical Analyst
Aug. 19, 2016
Richard Willey edited this comment Aug. 19, 2016
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The power required for a radio transmitter increases proportional to the square of the distance. Once you start putting walls in the way, it gets even worse. If you want to be able to sweep for hidden transmitters and the like, life gets much easier the further apart your two players are. Better yet, when you catch a player in possession of a transmitter it becomes a lot easier to land a conviction.

Moreover, moving the conditions of contest over to an electronic playing environment also means that you have perfect hand records so statistical inference starts becoming much much easier.
Aug. 19, 2016
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I continue to be incredulous that folks are so happy to set up witch hunts and empower star chambers and so resistant to practical changes that can nip the problems in the bud.

If you're serious about stopping folks from cheating, put them in separate rooms and require them to use computers to bid / play. Its as simple as that…

If you're not willing to put up with this, well I guess that the issue with cheating isn't all that serious to begin with…
Aug. 19, 2016
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When I originally posted this thread, I was being (in part) facetious.

Now that Nicolas has described the actual system that the ACBL is using, I am significant revising my estimate of the difficulty of cracking the ACBL hand records.

I would go so far as to say that the ACBL really needs to revise this ASAP…
Aug. 19, 2016
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thanks for clarifying. Makes much more sense now…
Aug. 19, 2016
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>Why is it a good idea that everyone knows that Hand 1
>is the seed? Why not let a different hand be the seed
>each time, and only have one trusted person know
>what that hand is?

Earlier in this thread I described a process that I would use for generating a seed for events.

1. Boards for major events like the Vanderbilt are generated immediately before each round of the event.

2. The seed for each round of the event is generated through a collaborative process. Hypothetically, we could deal a bridge hand out to four trusted individuals. Each individual would randomize the order of their cards and then privately enter cards into the dealing machine. The dealing machine uses this as a seed and generates all hands for this round of the event.

3. At the close of the event, each of the four individuals posts their hand. Anyone who is paranoid can validate that the boards match the hands.

We're trying to build the following properties into the system

1. People can publicly observe the key being generated

2. During the period that the key is kept secret, the key is distributed between four different people

3. The key is disclosed after the event and people can validate that the boards that were generated correspond to the key
Aug. 19, 2016
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>Why is it a good idea that everyone knows that Hand 1
>is the seed? Why not let a different hand be the seed
>each time, and only have one trusted person know
>what that hand is?

Because this kind of mind-blowingly stupid implementation would get fixed much more quickly.

(And I will go out on a limb here and make the assertion that any cipher scheme that publicly discloses its private key / or seed is about as dumb as you can find)

In case I'm not being clear, ALL of the hands that are being generated/disclosed should be outputs from the process rather than the entropy sources for the process.
Aug. 19, 2016
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> RF: An interesting point, Richard. Just as a theoretical discussion,
> instead of the software generating the hands sequentially (2…3…4…etc.),
> would it not create more security if the program were coded to
> generate the hands “randomly”? (7….16….9…4…etc.)

No

If all your randomness is coming from the same source, using some of that entropy to reorder boards doesn't buy you anything.

The only thing that matters is your seed length. Using some of it to play silly games is a distraction.
Aug. 19, 2016
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> RF: I certainly agree that the hand creation process and
> code should be kept as top secret as possible as part
> of best practices.

I'm willing to guess that almost all cryptographers would disagree with you.

Best practice in cryptography is that is that the security of a cipher should not change based on public knowledge of the underlying implementation. Indeed, you want as many eyes as possible looking at the code because that's how you find flaws.

Modern encryption standards are developed using public processes (and have been since at least the days of AES if not before)

“Security through obscurity” is normally used to disparage an idea.
Aug. 19, 2016
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To which I will add: I work with a bunch of cryptographers. The types of things that get cracked are FAR more secure than what was used by the ACBL in the past.

I genuinely believe that the only thing protecting us is that the amount of money that someone could make is relatively small. With this said and done, technology does not stand still. Methods that only a nation state actor could pull off 15 years ago start to become routine.

I would not rule out the possibility that someone could feed the first 4-5 hands in an online Vugraph into a computer and figure out what hands 16-32 will be before they are played. (Honestly, the main reason that I don't worry about this is that we transmit boards in real time, so there isn't all that much reason to crack them in advance). In the mean time, I really hope that the ACBL is generating new seeds between rounds for events like the Vanderbilt.

FWIW, I would really like to see a process in which

1. Boards for major events like the Vanderbilt are generated immediately before each round of the event.

2. The seed for each round of the event is generated through a collaborative process. Hypothetically, we could deal a bridge hand out to four trusted individuals. Each individual would randomize the order of their cards and then privately enter cards into the dealing machine. The dealing machine uses this as a seed and generates all hands for this round of the event.

3. At the close of the event, each of the 4 individuals posts their hand. Anyone who is paranoid can validate that the boards match the hands.

I had originally conceived of this type of system for an electronic playing environment. Honestly, it would work just as well for a system with dealing machines. (You just need a bit more lead time)
Aug. 19, 2016
Richard Willey edited this comment Aug. 19, 2016
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Hi Peter

Thanks for the numbers. Are the dues paid by various NBOs a linear function of the number of members of the NBO (For example, I'd be surprised if China were paying the same rate as other countries)
Aug. 18, 2016
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