Category Archive: Password

Mar 15 2016

Sound-Proof: an interesting authentication method

Four researchers of ETH Zurich (KARAPANOS N., MARFORIO C., SORIENTE C., and CAPKUN S.) have disclosed at last Usenix conference an innovative two-factor authentication method which is extremely user-friendly. As many current 2FA, it employs the user’s cell phone. However, the interaction with the phone is transparent to the user.

The user initiates the login with the typical login/password process on her or his device. Then, both this device and the user’s cell phone record the ambient sound. The two captured tracks are compared to verify whether they match. If they match, the authentication succeeds. The user’s cell phone captures the sound without the user having to interact with it. The phone may even be in the user’s pocket or shirt.

Obviously, this authentication does not prevent co-localized attacks, i.e., the attacker has the victim’s credentials and is near his victim. As the victim is not aware of the audio capture, the attack would succeed. Nevertheless, many scenarios are not vulnerable to co-localized attacks.

In the proof of concept, the cell phone performs the verification and returns the result to the login server. I do not find a reason this check could not be varied out by the server rather than by the phone. This modification would eliminate one security assumption of the trust model: the integrity of the software executing on the phone. The comparison would be more secure on the server.

A very interesting concept.

Karapanos, Nikolaos, Claudio Marforio, Claudio Soriente, and Srdjan Capkun. “Sound-Proof: Usable Two-Factor Authentication Based on Ambient Sound.” In 24th USENIX Security Symposium (USENIX Security 15), 483–98. Washington, D.C.: USENIX Association, 2015. https://www.usenix.org/conference/usenixsecurity15/technical-sessions/presentation/karapanos.

Jun 22 2015

Stealing account with mobile phone-based two-factor authentication

Attackers often entice users to become the weakest link.   Phishing and scams exploit the human weakness.  These attacks become even creepier if the attacker circumvents legitimate security mechanisms.   Two factor authentication offers better security than simple login/password.  The use of mobile phone as the second factor is becoming mainstream.  It is impossible to steal our account without stealing our phone.  We feel safer.  Should we?

Symantec reported a new used method to steal the account of users despite the use of a two-factor authentication.   Here is the scheme.

Mallory wants to gain access to Alice’s account.  He knows Alice email address and her mobile phone number as well as her account.  For a social engineer, this information is not difficult to collect.  It is part of the usual exploration phase before the actual hack.   Mallory contacts the service provider of Alice’s account and requests a password reset.  He selects the method that sends a digital code to Alice’s mobile phone.   The service provider sends an SMS to Alice’s mobile phone with this code. Simultaneously, Mallory sends an SMS to Alice impersonating the service provider.  Once more, this is not difficult as many providers do not use a specific number.  This SMS explains to Alice that there was some suspicious activity on her account.  To verify her account, she must reply to this SMS with the code that was sent previously to her.  Gullible Alice obeys.  Mallory has now the code that the service provider requests to reset Alice password.  Mallory gains entire access to Alice’s account with the involuntary help of Alice.

This type of attack can be used on most web services, e.g., webmails like gmail.  Obviously, Alice should not have replied to this SMS.  She should have followed the known procedure and not an unknown one.  She may have been cautious that the two phone numbers were different.

This is a perfect example of social engineering.   The only answer is education.  Therefore, spread this information around you,  The more people are aware, the less they will be prone to be hacked.  Never forget Law 6: You are the weakest link.

Feb 23 2015

Lenovo, Superfish, Komodia: a Man In The Middle story

Lenovo has made this week the headlines with the alleged malware: superfish.   Lenovo delivered  some PCx loaded with “bloatware” Superfish.  Superfish provides solution that performs visual search.  Seemingly, Superfish designed a software that allowed to place contextual ads on the web browsing experience.   To perform this highjacking, superfish uses a software stack from Komodia:  SSL Digestor.  According to the site of Komodia:

Our advanced SSL hijacker SDK is a brand new technology that allows you to access data that was encrypted using SSL and perform on the fly SSL decryption. The hijacker uses Komodia’s Redirector platform to allow you easy access to the data and the ability to modify, redirect, block, and record the data without triggering the target browser’s certification warning.

How does Komodia do the decryption without triggering the certificate validation of the browser?   The CERT has disclosed on Thursday the trick with its vulnerability note VU#529496.

Komodia Redirector with SSL Digestor installs non-unique root CA certificates and private keys, making systems broadly vulnerable to HTTPS spoofing

Komodia install stealthily its own root certificate within the browsers’ CA repository.   The stack holds its private key. This allows to ‘self-sign’ certificate to forge SSL connection.  The software then generates a typical Man In The Middle.   Despite the private key was encrypted, it was possible to extract some corresponding private keys (easy to guess the password; komodia).  This means that as long as the root key is not erased from browsers’ repository, an attacker may use the corresponding private key.  The attacker may sign malware that would be accepted by the machine, and generate phony certificates for phishing.   In other words, other principals than Superfish may use the hack for infecting Lenovo computers.

Lenovo provided a patch that removed the Superfish application.   Unfortunately, the patch does not erase the malicious certificate.  Microsoft provided such patch, and Mozilla should soon revoke it.

This is a perfect example of supply chain attack. The main difference is that the supplier voluntarily infected its product.    Do never forget law 4: Trust No One.

PS:  at the time of writing, the Komodia site was down, allegedly for a DOS.  It may also be because too many people try to visit the site.

Nov 20 2014

Who is monitoring your baby?

Data Watchdog announced that a Russian website featured a database listing of about 73,000  streaming IP webcams or CCTV whose owners are not aware that their webcam is broadcasting the video. The webcams are located all over the world. They are used for offices, baby monitoring, shop’s monitoring, pubs, etc.  All major manufacturers were present amongst the breached webcams.  The webcams were discovered by Internet scanning and trying the default password.  This is a good illustration of Law 8: If you watch Internet, Internet is watching you.  The UK Information Commissioner’s Office recommends changing the default password of the camera and when not needed disable remote access.

The site claims to do that for educational purpose.   This is what the site claims when accessing it.  It seems that it is efficient, as there are less and less listed feeds.

Sometimes administrator (possible you too) forgets to set the default password on security surveillance system, online camera or DVR. This site now contains access only to cameras without a password and it is fully legal. Such online cameras are available for all internet users. To browse cameras just select the country or camera type.

This site has been designed in order to show the importance of the security settings. To remove your public camera from this site and make it private the only thing you need to do is to change your camera default password.

Several interesting lessons:

  • As usual, default password are incriminated.  Users, and even professionals as it seems that CCTV are also listed, do not change the default password.  Manufacturers may not want to enforce the change of the default password, as it creates issues when users forget their password, but they should at least propose it the first time the user boots the device.
  • People are not good with security.  With the Internet of Things (IoT), there will be more and more connected devices.  This means that there will be more and more vulnerable devices on the Net.  IoT may make the Internet more brittle.
  • Who will inform the owners of these spied webcams that they are spied?  The remedy is simple, but the victims should at least be aware that they should apply this remedy.

By the way, did you change the default password of all your devices?  If not, I plead you to do so.

Jan 14 2014

A graphical password solution: PixelPin

Graphical passwords are an alternative to usual textual passwords. They use an image as main support and image handling such as pointing position in the picture as entry mode. They can be convenient on tactile screens, more difficult for robots to mimic human behavior, and claimed to offer better memory resilience.

Since early 1990s, the literature has been rather extensive in the field. Technicolor published several papers in the field (search for Maetz and Eluard). But we rarely see a product that implements such a solution.

UK-based company, PixelPin offers such a solution. It is based on Bonder’s seminal patent (5559961). When registering, you select one image as a support and four points in the image in a given order. When answering the challenge, you have to select the four points in the initial order. To limit risks of shoulder surfing, the precision of positioning is rather fine (at least on a computer). After 5 attempts, the account is locked for 15 minutes. Reset sends a reset token via the email used to register.

To increase memory resilience, and to ease the positioning you should select a picture with clear identified salient points else you will be quickly locked out. Of course, using too obvious salient points reduces the space of “keys” to explore.

The main issue is the network effect needed for such solution. It will be efficient if the sites are common and often visited, else your memory will fade. Unfortunately, I did not find many sites using PixelPin. The startup was launched beginning last year.

Dec 17 2013

Preventing weak passwords by reading your mind

This is what the site Telepathwords proposes. This site estimates the strength of a password. The interesting part of this Microsoft Research site is the used heuristics.

After each dialed character, it attempts to guess what the next character. if it guessed right, then the character is considered as weak (indicated by a red cross). How does it guess the characters?

Telepathwords tries to predict the next character of your passwords by using knowledge of:

  • common passwords, such as those made public as a result of security breaches
  • common phrases, such as those that appear frequently on web pages or in common search queries
  • common password-selection behaviors, such as the use of sequences of adjacent keys

It considers the password strong if it has at least six non guessable characters.

Of course, the strength of the system relies on the richness of its dictionaries of common passwords and common phrases. Obviously, the game was to play with it. My first thought was that it would be purely English centric. Thus, I tried French and the first one was azerty. Azerty of course was weak. “abrutifrançais” (or French idiot) was a strong password even without the special character ç  “Je pense donc je suis” was also middle (as it guessed the end) . Let’s go further and switch to Latin. “CogitoErgoSum” was also weak as well as “venividivici”.  But “aleajactaest” was extremely robust!!

For the fun, I checked consistency with Microsoft Password Checker. The answers are not consistent. For instance, “CogitoErgoSum” turns out to be strong whereas “aleajactaest” is medium.

As always, it is always rather easy to trick this type of sites. Nevertheless, the site clearly explains that it will not detect all weak passwords, especially from languages other than English

Sep 10 2013

Has NSA broken the crypto?

With the continuous flow of revelations by Snowden, there is not one day without somebody asking me if crypto is dead.  Indeed, if you read some simplifying headlines, it looks like the Internet is completely unsecure.

 

Last Friday, Bruce Schneier published an excellent paper in the guardian : “NSA surveillance: a guide to staying secure.”  For two weeks, he has analyzed documents provided by Snowden.   From this analysis, he drives some conclusions and provides some recommendations.  In view of the security profile of Bruce, we may trust the outcome.  I recommend the readers to read the article.

My personal highlights from this article.

  • The documents did not present any outstanding mathematical breakthrough.   Thus, algorithms such as AES are still secure.
  • To “crack” encrypted communications, NSA uses the same tools than hackers but at a level of sophistication far higher.   They have a lot of money.  The tricks used:
    • Look for used weak algorithms
    • Look for weak passwords with dictionary attacks
    • Powerful brute force attacks
  • The two most important means are:
    • Implementing back doors and weakening commercial implementations (poor random generator, poor factors in Elliptic Curve Cryptosystems (ECC), leaking keys…).   The same is true for hardware.

As was revealed today, the NSA also works with security product vendors to ensure that commercial encryption products are broken in secret ways that only it knows about.

    • Compromising the computer that will encrypt or decrypt.  If you have access to the data before it is secured, then you do not care about the strength of the encryption.

These are hacker tools designed by hackers with an essentially unlimited budget. What I took away from reading the Snowden documents was that if the NSA wants in to your computer, it’s in. Period.

His recommendations are common sense.   The most interesting one is to avoid using ECC as NSA seems to influence the choice of weak curves and constants in the curve.

 

His final statement

Trust the math.

is OK, but I would add “Do not trust the implementation.”  Always remember law 4: Trust No One.

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