A Modern Reappraisal of the One-Time Pad Cipher.
in [Cryptography]
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From: David Eather on 4 May 2010 21:50 On 4/05/2010 5:38 PM, Kristian Gj�steen wrote: > nemo_outis<abc(a)xyz.com> wrote: >> However, cops' "suspicions" are going to be very thin gruel to >> put up aginst a defence lawyer's "M'lud, my client fully >> decrypted the file as has been plainly shown. He used a >> standard cryptographic method as has been explained to the >> Court. There can be no doubt of his full cooperation and >> compliance with the law in this matter." > > Unfortunately, judges are usually not idiots. Pulling this off > convincingly is going to be very difficult. > Yes, and jail (gaol) is full of people who were "too smart" to get caught.
From: David Eather on 4 May 2010 22:01 On 5/05/2010 8:12 AM, unruh wrote: > On 2010-05-04, Maaartin<grajcar1(a)seznam.cz> wrote: >> On May 4, 9:18 pm, unruh<un...(a)wormhole.physics.ubc.ca> wrote: >>> On 2010-05-04, Maaartin<grajc...(a)seznam.cz> wrote: >>> >>>> On May 4, 2:38 am, "robertwess...(a)yahoo.com"<robertwess...(a)yahoo.com> >>>> wrote: >>>>> True, but can you rely on both copies of the key (yours and your >>>>> client's) having been secure for five years? >>> >>>> Maybe. But using a OTP for five years would be no better (except that >>>> stealing a couple of GB is a bit harder). >>> >>>> On May 4, 9:38 am, Kristian Gj?steen<kristiag+n...(a)math.ntnu.no> >>>> wrote: >>>>> Unfortunately, judges are usually not idiots. Pulling this off >>>>> convincingly is going to be very difficult. >>> >>>> This is not his job. The judge must proof him guilty, not the other >>>> way round. At least in theory. >>> >>> Yes, it is his job of deciding if you are lying or not. >> >> He must either *proof* me lying or let it be. At least in theory. > > No, just "beyond a reasonable doubt" if it is criminal case in a common > law jurisdiction. That is not mathematical proof. > It's even worse than that. A judge only has to satisfy *themselves* that you are *probably* lying. A jury has to satisfy itself either *beyond reasonable doubt* or *on the balance of probability* from the evidence *of the entire case* of which your otp will be only one small part, considered amongst many other parts at best. (sorry for all the asterisks) >> >>> Most (not all) judges try to apply the law. They also know that many >>> people who come before them lie (just as you are advocating doing). >> >> It surely depends on the country. > > No in all countries some (many) people who come before judges lie. >> >>>> Why? It's just a two-time pad, a stupid but legitimate way how to save >>>> some space. >>> >>> Two keys the length of the file, and one file, saves space how? >> >> These two keys leads to two different plaintexts. The one-time pad >> needs 4 files for 2 porns. The two-time pad needs only 3. >> >>>> Or anything else. If the police find anything in a confiscated >>>> computer, why should anybody ever think it was really there? Maybe if >>>> they would do two copies instead, one for them and one for a notary, >>>> it could make sense. >>> >>> They do. They are supposed to preserve the chain of evidence. Make a >>> copy of the hard drive and only work on the copy. >> >> First, the computer gets confiscated. This is obviously unnecessary >> and a clear indication of bad will (unless they're stopping you from >> doing criminal offence, which is unproven at the moment). Thereafter >> there's no reason to believe that they're not modifying the data. >> Again, it depends on the country. >> >> I wonder how anybody wants to prove that I'm not just testing my >> newest RNG. Especially when there are many RNGs and statistical test >> suits on my computer.
From: J.D. on 4 May 2010 23:35 On May 4, 10:01 pm, David Eather <eat...(a)tpg.com.au> wrote: > > >>>> This is not his job. The judge must proof him guilty, not the other > >>>> way round. At least in theory. > > >>> Yes, it is his job of deciding if you are lying or not. > > >> He must either *proof* me lying or let it be. At least in theory. > > > No, just "beyond a reasonable doubt" if it is criminal case in a common > > law jurisdiction. That is not mathematical proof. > > It's even worse than that. A judge only has to satisfy *themselves* that > you are *probably* lying. A jury has to satisfy itself either *beyond > reasonable doubt* or *on the balance of probability* from the evidence > *of the entire case* of which your otp will be only one small part, > considered amongst many other parts at best. (sorry for all the asterisks) > I don't know about other countries, but in American (and I think English) courts this is not quite correct: First off, in criminal trials the defendant always has the right to a jury (except possibly where the maximum penalty is just a fine or a very short prison sentence). In trials where there is a jury, the jury acts as the "finder of fact" -- they are tasked to decide whether you are lying or not (and every other factual matter). The judge is the "finder of law" -- he decides legal questions that arise (such as what evidence is legally permissible, what objections have legal merit, and the like). Deciding whether a witness is lying is not a legal question, it is a factual matter. If the defendant waives the right to a jury (or the penalty is just a fine or short sentence) then the judge may act also as the finder of fact (s/he wears two hats, if you will). However the standard of proof in criminal trials is the same whether the finder of fact is a judge or a jury -- beyond a reasonable doubt. If the judge is acting as the finder of fact and decides that you are only "probably" lying, but cannot be certain of that fact beyond a reasonable doubt, then he or she is not supposed to find you guilty (assuming you being a liar = you are guilty). Of course, it is hard to know if judges do what they are 'supposed' to do when making such decisions; but in that regard they are on the same level as juries, who are also 'supposed' to not find you guilty unless they are certain beyond a reasonable doubt. In civil litigation, the standard of proof is lower -- but it is lower for the finder of fact whether that is a judge or a jury; and, like criminal trials, it is exactly the same for both kinds of finder of fact.
From: David Eather on 5 May 2010 01:33 On 5/05/2010 1:35 PM, J.D. wrote: > On May 4, 10:01 pm, David Eather<eat...(a)tpg.com.au> wrote: > >> >>>>>> This is not his job. The judge must proof him guilty, not the other >>>>>> way round. At least in theory. >> >>>>> Yes, it is his job of deciding if you are lying or not. >> >>>> He must either *proof* me lying or let it be. At least in theory. >> >>> No, just "beyond a reasonable doubt" if it is criminal case in a common >>> law jurisdiction. That is not mathematical proof. >> >> It's even worse than that. A judge only has to satisfy *themselves* that >> you are *probably* lying. A jury has to satisfy itself either *beyond >> reasonable doubt* or *on the balance of probability* from the evidence >> *of the entire case* of which your otp will be only one small part, >> considered amongst many other parts at best. (sorry for all the asterisks) >> > > I don't know about other countries, but in American (and I think > English) courts this is not quite correct: > > First off, in criminal trials the defendant always has the right to a > jury (except possibly where the maximum penalty is just a fine or a > very short prison sentence) or it is decided that the case may involve matters of national security - in which case anything from a star chamber to a military court might be the process (what ever happened in gitmo?) . Or you waive the right to a jury either of your own free will or by coercion, or if there is a suspicion (real or imagined) of jury tampering you may be heard without a jury. In any case, what the judge thinks is relevant as he may decide what evidence is in or out and he may instruct the jury what weight to give a piece of evidence or how to interpret it or even throw out a verdict as having no basis in law (and all of these have happened in US courts). The "courts" are not so simple as it may seem. <snip>
From: MrD on 5 May 2010 03:22
David Eather wrote: > On 5/05/2010 1:35 PM, J.D. wrote: >> On May 4, 10:01 pm, David Eather<eat...(a)tpg.com.au> wrote: >> >>> >>>>>>> This is not his job. The judge must proof him guilty, not the other >>>>>>> way round. At least in theory. >>> >>>>>> Yes, it is his job of deciding if you are lying or not. >>> >>>>> He must either *proof* me lying or let it be. At least in theory. >>> >>>> No, just "beyond a reasonable doubt" if it is criminal case in a common >>>> law jurisdiction. That is not mathematical proof. >>> >>> It's even worse than that. A judge only has to satisfy *themselves* that >>> you are *probably* lying. A jury has to satisfy itself either *beyond >>> reasonable doubt* or *on the balance of probability* from the evidence >>> *of the entire case* of which your otp will be only one small part, >>> considered amongst many other parts at best. (sorry for all the >>> asterisks) >>> >> >> I don't know about other countries, but in American (and I think >> English) courts this is not quite correct: >> >> First off, in criminal trials the defendant always has the right to a >> jury (except possibly where the maximum penalty is just a fine or a >> very short prison sentence) > > or it is decided that the case may involve matters of national security > - in which case anything from a star chamber to a military court might > be the process (what ever happened in gitmo?) . Gitmo is not a common law jurisdiction (AIUI). -- MrD. |