Author Archives: eric

SHA-3 is born

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In 2005, the first serious attacks on the widely use hash function SHA-1 were published.  Researchers were able to generate some collisions.   The new generation SHA-2 was also prone to these attacks.  In 2007, NIST launched a contest to select the future replacing algorithm.  At the first round, there were 63 submissions.  The second round kept only five algorithms.   On Tuesday, NIST published the winner: KECCAK

KECCAK was designed by researchers from STMicroelectronics and NXP.  According to NIST, KECCAK won because it was elegantly simple and had higher performance in hardware implementation than the other competitors.  As it is foreseen that SHA-3  may be used in many lite weight embedded devices (smart dust, intelligent captors, RFID…) , this was a strong asset.  No surprise that its implementation was optimized for hardware; Its four fathers are working for companies designing such chipset.  STMicroelectronics is one of the leaders in secure components for smart cards, whereas NXP is the leader in NFC.  Another interesting argument is as KECCAK uses totally different principles than SHA-2, attacks that would work on SHA-2, most likely will not work for SHA-3.

On September 24, 2012, Bruce Schneier, one of the five finalists with his Skein algorithm, called for a “no award”.  Currently, SHA-512 is still secure for many years.  Thus,according to him, there was no need to switch to another algorithm.

In its announcement of the winner, NIST confirmed that

SHA-2 has held up well and NIST considers SHA-2 to be secure and suitable for general use.

Thus, be not afraid when you will still find SHA-2 in designs for the coming years.  We’re safe.  It will take several years to tame this new algorithm.  Nevertheless, NIST estimates that having a successor to SHA-2, if ever it weakens, is a good insurance policy.

WHITEHAT SECURITY WEBSITE STATISTICS REPORT

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Every semester, WhiteHat security publishes its website security statistics report.   It provides a good insight on the evolution of the landscape.   Its reading is interesting although the data must be taken very carefully rather than ground truth.  To be honest, the author clearly highlights this point.

 

Some of the points that interested me.

  • The number of serious vulnerabilities is decreasing each year.  Unfortunately, the deviation is large.  Some sites presents hundreds of serious vulnerabilities whereas banking sites present only a few (hopefully).   Here also, this is a best case scenario. image
  • Number one type of vulnerability: XSS, followed by Information leakage.   The famous SQL injection appears only in 8th position.  But we know how SQL injection can be devastative.
  • In the ranking of type of companies, as already said banking industry are the best students in the class with only 17 serious vulnerabilities.  Interestingly, social networks are not doing a bad job being at 3rd rank with 31 vulnerabilities

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  • An interesting, and worrying, data: the vulnerability reopen rates.  20% of the vulnerabilities have been reopened at least once!  The more serious the vulnerability, the higher the likelihood of reopening.

 

If you’re interested in collecting this type of trends, then read this white paper.

Carnage on French piracy (2)

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In July 2008, French cybercops arrested two video pirate groups:  CaRNaGe that was specialized in the capture of content, and Cinefox that managed a distribution site.  Four years later, the French justice took its decision.   CaRNaGe members (2 people) have been sentenced to 3-6 months of conditional jail and 410,000€.   Cinefox members (3 people) have been sentenced to 6 months of conditional jail and 710,000€.

ReDigi.com the resale locker

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indexI must confess that I became aware of this interesting initiative only this summer, although ReDigi operates since October 2011.

ReDigi is a site that allows you either to resell your music songs that you do not want anymore, or purchase music songs that people do not want anymore.  In other words, a second-hand market for music.

How does it work, from the user point of view:

  1. Alice user subscribes to the service
  2. ReDigi locates the songs Alice may resell (either purchase with iTunes, or ReDigi)
  3. Alice selects the songs to sell and reDigi stores them in the cloud while wiping out the copies on the computers
  4. As long as the song is not yet sold, Alice can stream it
  5. Once Bob purchased it, she cannot anymore listen to it.
  6. If ever a copy of the sold song appears again on Alice’s device(s), she is notified.

 

How does it work (partly using the details provided by ReDigi in a court trial, an interview, and my guesses)

  1. She has to install a software called Music Manager
  2. Music Manager explores the directories and spots the iTunes and ReDigi songs.  It most probably directly jumps to the FairPlay protected directory to find the licenses.  It checks if it is legal (in other words if it can access the key, then meaning that it was bound to the device)
  3. It uploads the file (and probably the license) to the cloud and erases the accessible song.  At next sync, all iTunes copies should disappear.
  4. The uploaded copy is marked as such until it is sold
  5. Mark it for somebody else.  I would like to know if they rebuild their own license or a new iTunes license.
  6. During phase 3, it extracts a fingerprint of the song.  Music Manager scouts the hard drive to find copies.  I was not able to find if the fingerprint is a basic crypto hash (md5) or a real audio fingerprint.  If it is the second case, then funny things may happen. 
    Alice purchased Song1 on iTunes.  Later she purchase the full album on a CD.  Thus, she resells the iTunes song1, and rips her CD.  A legit copy of Song1 will reappear on her drive.  Music Manager will complain (ReDigi claims that after numerous complaints that would not be obeyed, i.e., the song is erased, the subscription is cancelled)
    Obviously, if it is just the hash, then the system can be easily bypassed.

 

The interesting question is not if the system can be bypassed.  I am sure that the readers of this blog have already guessed at least one or two ways to hack it.  It is not complex, and I will not elaborate on it.

 

The interesting question is to know if it is legal to resell a digital song.  There is a US first sale doctrine that allows to resell your own goods, nevertheless the answer may perhaps not be so trivial.  See this article.  We will soon have a (first) answer.  On January 2012, Capitol Records filed a suit against ReDigi.  On February 2012, the district court rejected the preliminary injunction.  Oral arguments should start on October 5.  This article gives a good summary of the legal case. 

Google’s anti-piracy new step (2)

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In January 2011, Google updated its auto completion feature to become more copyright friendly.  In August 2012, Google made another movement in this direction.   Ami Singhal, SVP Engineering, announced that the ranking algorithm will now take into account the number of valid copyright removal notices.  Thus, in theory, sites with illegal content should appear lower in the pages.

 

Does it work?  I used the same example than in related post: Black swan.  The situation is better for auto completion.   If you try with “Black swan pirate movie”, you do not find illegal content on the first pages.  Nevertheless, if you try “Black Swan torrent”, the first page is only about illegal torrents; the first result points to the pirate bay!

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By the way, when trying “Black Swan pirate movie” on Microsoft’s bing, the third proposed result points to streaming sites.

Google receives an astounding number of removal notices.  According to Google’s transparency report, it received about 5,900,000 notices to remove URL for copyright infringement. 

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Source: http://www.google.com/transparencyreport/removals/copyright/ on 2012, September 3.

If they are all executed, it means that the execution is done automatically without a manual verifcation.  There is no way to do it with systematic human supervision.  May be Google uses a first step of screening with automatic fingerprinting recognition, and then manually examine the non detected ones.  If somebody has a pointer that describes this process, I would love to read it.   Or an educated guess?

Why do Nigerian scammers say they are from Nigeria?

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Nigerian scam is a generic term for the category of scams that always follow the same scheme: the widow/lawyer/son/exiled person has a huge sum of money blocked somewhere.  They need the help of a trusted person to exfiltrate this money.  You are this person.  Of course, you will be nicely rewarded for your help.  Obviously, if you accept to help, soon the scammer will ask a minimum fund to be able to make the paper or bribe the proper officials… Of course, at the end, no money transfer to you.   Nigerian scam is a very old trick.

 

As Nigerian scam is old and well-known, the question why the attackers still use such an obvious trick is a valid one.  And the basic answer that attackers may be stupid is not appropriate.  HERLEY Cormac, from Microsoft Research, provides a very convincing answer.

 

Scammers have also false positive.  This type of scams needs a lengthy interaction with the target.  This interaction has a cost (time, effort).   When starting the interaction, the attacker would rather like to have no false positive.  Ideally, the attacker should only start with viable targets, i.e. targets that will carry the interaction till the succesful skimming.   Intuitively, you may guess that the more gullible the target is, the higher the chance of success is.  Therefore, using such a worn-down trick filters the initial respondents.  It skims out only the most gullible persons. Thus, it lowers the rate of false positive.

 

Cormac analyses the typical Receiver Operator Characteristic curves that are usually used to draw the tradeoff between true and false positive of classifiers.  He checks for the optimal operating point.   He analyzes the impact of density (i.e. the ratio of viable targets) and the quality of the classifier.   Then, he applies the outcomes to the Nigerian scams.   He shows that the “dumbness” of the mail is a good classifier and that the attackers try to operate in a better overall profit.

 

This paper is interesting to read as it uses the usual maths for classifiers to analyze the impact of false positives on the financial gain of the attacker.  It takes also the stance that not all scams are costless to attackers.

 

The paper reference:

C. Herley, “Why do Nigerian Scammers Say They are from Nigeria?,” Berlin, Germany: Microsoft Research, 2012 available at http://research.microsoft.com/apps/pubs/?id=167719.

Is French HADOPI law dead? (10)

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In 2009, the French government launched HADOPI.  The HADOPI is the institution responsible to handle the graduated response to copyright infringement via three escalating strikes.  Three years later comes the time of the first bilan.

 

HADOPI sent out one million warning emails (first strike level) and 99,000 registered letters (second strike level) which resulted to 134 cases examined for prosecution.   Today, no case reached the ultimate strike level, i.e. disconnection of the infringer from Internet.  The reported cost is of 12M€.

 

In a recent interview to French newspaper “Le nouvel Observateur”, the French minister of culture, Aurélié FiLIPPETTI severely judged the results of HADOPI.

Ca coûte quand même 12 millions d’euros, 60 agents travaillent, pour un résultat qui me semble au final bien mince. Dans un contexte budgétaire serré, il faut avoir un souci d’efficacité, de réconciliation entre les artistes et les publics, et trouver des solutions qui soient réelles et qui permettent vraiment de financer la création et non plus se payer de mots.

A possible English translation is

This costs 12 million euro.  60 agents work for a result which seems to me light. In a tight budget context, it is mandatory to be efficient,  to reconciliate the artists and the audience, and to find solutions which are real and that really fund creation and not to talk a lof of rubbish.

 

The minister claimed that she’d rather reduce the cost of solutions that do not have proven efficiency.   Thus, what is the future of HADOPI?

 

The interview can be found here and here.  Sorry, it is in French.