Entries Tagged "security awareness"

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Research on the Timing of Security Warnings

fMRI experiments show that we are more likely to ignore security warnings when they interrupt other tasks.

A new study from BYU, in collaboration with Google Chrome engineers, finds the status quo of warning messages appearing haphazardly­ — while people are typing, watching a video, uploading files, etc.­ — results in up to 90 percent of users disregarding them.

Researchers found these times are less effective because of “dual task interference,” a neural limitation where even simple tasks can’t be simultaneously performed without significant performance loss. Or, in human terms, multitasking.

“We found that the brain can’t handle multitasking very well,” said study coauthor and BYU information systems professor Anthony Vance. “Software developers categorically present these messages without any regard to what the user is doing. They interrupt us constantly and our research shows there’s a high penalty that comes by presenting these messages at random times.”

[…]

For part of the study, researchers had participants complete computer tasks while an fMRI scanner measured their brain activity. The experiment showed neural activity was substantially reduced when security messages interrupted a task, as compared to when a user responded to the security message itself.

The BYU researchers used the functional MRI data as they collaborated with a team of Google Chrome security engineers to identify better times to display security messages during the browsing experience.

Research paper. News article.

Posted on August 22, 2016 at 7:03 AMView Comments

Over 700 Million People Taking Steps to Avoid NSA Surveillance

There’s a new international survey on Internet security and trust, of “23,376 Internet users in 24 countries,” including “Australia, Brazil, Canada, China, Egypt, France, Germany, Great Britain, Hong Kong, India, Indonesia, Italy, Japan, Kenya, Mexico, Nigeria, Pakistan, Poland, South Africa, South Korea, Sweden, Tunisia, Turkey and the United States.” Amongst the findings, 60% of Internet users have heard of Edward Snowden, and 39% of those “have taken steps to protect their online privacy and security as a result of his revelations.”

The press is mostly spinning this as evidence that Snowden has not had an effect: “merely 39%,” “only 39%,” and so on. (Note that these articles are completely misunderstanding the data. It’s not 39% of people who are taking steps to protect their privacy post-Snowden, it’s 39% of the 60% of Internet users — which is not everybody — who have heard of him. So it’s much less than 39%.)

Even so, I disagree with the “Edward Snowden Revelations Not Having Much Impact on Internet Users” headline. He’s having an enormous impact. I ran the actual numbers country by country, combining data on Internet penetration with data from this survey. Multiplying everything out, I calculate that 706 million people have changed their behavior on the Internet because of what the NSA and GCHQ are doing. (For example, 17% of Indonesians use the Internet, 64% of them have heard of Snowden and 62% of them have taken steps to protect their privacy, which equals 17 million people out of its total 250-million population.)

Note that the countries in this survey only cover 4.7 billion out of a total 7 billion world population. Taking the conservative estimates that 20% of the remaining population uses the Internet, 40% of them have heard of Snowden, and 25% of those have done something about it, that’s an additional 46 million people around the world.

It’s probably true that most of those people took steps that didn’t make any appreciable difference against an NSA level of surveillance, and probably not even against the even more pervasive corporate variety of surveillance. It’s probably even true that some of those people didn’t take steps at all, and just wish they did or wish they knew what to do. But it is absolutely extraordinary that 750 million people are disturbed enough about their online privacy that they will represent to a survey taker that they did something about it.

Name another news story that has caused over ten percent of the world’s population to change their behavior in the past year? Cory Doctorow is right: we have reached “peak indifference to surveillance.” From now on, this issue is going to matter more and more, and policymakers around the world need to start paying attention.

Related: a recent Pew Research Internet Project survey on Americans’ perceptions of privacy, commented on by Ben Wittes.

This essay previously appeared on Lawfare.

EDITED TO ADD (12/15): Reddit thread.

EDITED TO ADD (12/16): Slashdot thread.

EDITED TO ADD (1/23): This essay has been translated into German.

Posted on December 15, 2014 at 6:07 AMView Comments

Paying People to Infect their Computers

Research paper: “It’s All About The Benjamins: An empirical study on incentivizing users to ignore security advice,” by Nicolas Christin, Serge Egelman, Timothy Vidas, and Jens Grossklags.

Abstract: We examine the cost for an attacker to pay users to execute arbitrary code — potentially malware. We asked users at home to download and run an executable we wrote without being told what it did and without any way of knowing it was harmless. Each week, we increased the payment amount. Our goal was to examine whether users would ignore common security advice — not to run untrusted executables­ — if there was a direct incentive, and how much this incentive would need to be. We observed that for payments as low as $0.01, 22% of the people who viewed the task ultimately ran our executable. Once increased to $1.00, this proportion increased to 43%. We show that as the price increased, more and more users who understood the risks ultimately ran the code. We conclude that users are generally unopposed to running programs of unknown provenance, so long as their incentives exceed their inconvenience.

The experiment was run on Mechanical Turk, which means we don’t know who these people were or even if they were sitting at computers they owned (as opposed to, say, computers at an Internet cafe somewhere). But if you want to build a fair-trade botnet, this is a reasonable way to go about it.

Two articles.

Posted on June 19, 2014 at 6:28 AMView Comments

Choosing Secure Passwords

As insecure as passwords generally are, they’re not going away anytime soon. Every year you have more and more passwords to deal with, and every year they get easier and easier to break. You need a strategy.

The best way to explain how to choose a good password is to explain how they’re broken. The general attack model is what’s known as an offline password-guessing attack. In this scenario, the attacker gets a file of encrypted passwords from somewhere people want to authenticate to. His goal is to turn that encrypted file into unencrypted passwords he can use to authenticate himself. He does this by guessing passwords, and then seeing if they’re correct. He can try guesses as fast as his computer will process them — and he can parallelize the attack — and gets immediate confirmation if he guesses correctly. Yes, there are ways to foil this attack, and that’s why we can still have four-digit PINs on ATM cards, but it’s the correct model for breaking passwords.

There are commercial programs that do password cracking, sold primarily to police departments. There are also hacker tools that do the same thing. And they’re really good.

The efficiency of password cracking depends on two largely independent things: power and efficiency.

Power is simply computing power. As computers have become faster, they’re able to test more passwords per second; one program advertises eight million per second. These crackers might run for days, on many machines simultaneously. For a high-profile police case, they might run for months.

Efficiency is the ability to guess passwords cleverly. It doesn’t make sense to run through every eight-letter combination from “aaaaaaaa” to “zzzzzzzz” in order. That’s 200 billion possible passwords, most of them very unlikely. Password crackers try the most common passwords first.

A typical password consists of a root plus an appendage. The root isn’t necessarily a dictionary word, but it’s usually something pronounceable. An appendage is either a suffix (90% of the time) or a prefix (10% of the time). One cracking program I saw started with a dictionary of about 1,000 common passwords, things like “letmein,” “temp,” “123456,” and so on. Then it tested them each with about 100 common suffix appendages: “1,” “4u,” “69,” “abc,” “!,” and so on. It recovered about a quarter of all passwords with just these 100,000 combinations.

Crackers use different dictionaries: English words, names, foreign words, phonetic patterns and so on for roots; two digits, dates, single symbols and so on for appendages. They run the dictionaries with various capitalizations and common substitutions: “$” for “s”, “@” for “a,” “1” for “l” and so on. This guessing strategy quickly breaks about two-thirds of all passwords.

Modern password crackers combine different words from their dictionaries:

What was remarkable about all three cracking sessions were the types of plains that got revealed. They included passcodes such as “k1araj0hns0n,” “Sh1a-labe0uf,” “Apr!l221973,” “Qbesancon321,” “DG091101%,” “@Yourmom69,” “ilovetofunot,” “windermere2313,” “tmdmmj17,” and “BandGeek2014.” Also included in the list: “all of the lights” (yes, spaces are allowed on many sites), “i hate hackers,” “allineedislove,” “ilovemySister31,” “iloveyousomuch,” “Philippians4:13,” “Philippians4:6-7,” and “qeadzcwrsfxv1331.” “gonefishing1125” was another password Steube saw appear on his computer screen. Seconds after it was cracked, he noted, “You won’t ever find it using brute force.”

This is why the oft-cited XKCD scheme for generating passwords — string together individual words like “correcthorsebatterystaple” — is no longer good advice. The password crackers are on to this trick.

The attacker will feed any personal information he has access to about the password creator into the password crackers. A good password cracker will test names and addresses from the address book, meaningful dates, and any other personal information it has. Postal codes are common appendages. If it can, the guesser will index the target hard drive and create a dictionary that includes every printable string, including deleted files. If you ever saved an e-mail with your password, or kept it in an obscure file somewhere, or if your program ever stored it in memory, this process will grab it. And it will speed the process of recovering your password.

Last year, Ars Technica gave three experts a 16,000-entry encrypted password file, and asked them to break as many as possible. The winner got 90% of them, the loser 62% — in a few hours. It’s the same sort of thing we saw in 2012, 2007, and earlier. If there’s any new news, it’s that this kind of thing is getting easier faster than people think.

Pretty much anything that can be remembered can be cracked.

There’s still one scheme that works. Back in 2008, I described the “Schneier scheme”:

So if you want your password to be hard to guess, you should choose something that this process will miss. My advice is to take a sentence and turn it into a password. Something like “This little piggy went to market” might become “tlpWENT2m”. That nine-character password won’t be in anyone’s dictionary. Of course, don’t use this one, because I’ve written about it. Choose your own sentence — something personal.

Here are some examples:

  • WIw7,mstmsritt… = When I was seven, my sister threw my stuffed rabbit in the toilet.
  • Wow…doestcst = Wow, does that couch smell terrible.
  • Ltime@go-inag~faaa! = Long time ago in a galaxy not far away at all.
  • uTVM,TPw55:utvm,tpwstillsecure = Until this very moment, these passwords were still secure.

You get the idea. Combine a personally memorable sentence with some personally memorable tricks to modify that sentence into a password to create a lengthy password. Of course, the site has to accept all of those non-alpha-numeric characters and an arbitrarily long password. Otherwise, it’s much harder.

Even better is to use random unmemorable alphanumeric passwords (with symbols, if the site will allow them), and a password manager like Password Safe to create and store them. Password Safe includes a random password generation function. Tell it how many characters you want — twelve is my default — and it’ll give you passwords like y.)v_|.7)7Bl, B3h4_[%}kgv), and QG6,FN4nFAm_. The program supports cut and paste, so you’re not actually typing those characters very much. I’m recommending Password Safe for Windows because I wrote the first version, know the person currently in charge of the code, and trust its security. There are ports of Password Safe to other OSs, but I had nothing to do with those. There are also other password managers out there, if you want to shop around.

There’s more to passwords than simply choosing a good one:

  1. Never reuse a password you care about. Even if you choose a secure password, the site it’s for could leak it because of its own incompetence. You don’t want someone who gets your password for one application or site to be able to use it for another.
  2. Don’t bother updating your password regularly. Sites that require 90-day — or whatever — password upgrades do more harm than good. Unless you think your password might be compromised, don’t change it.
  3. Beware the “secret question.” You don’t want a backup system for when you forget your password to be easier to break than your password. Really, it’s smart to use a password manager. Or to write your passwords down on a piece of paper and secure that piece of paper.
  4. One more piece of advice: if a site offers two-factor authentication, seriously consider using it. It’s almost certainly a security improvement.

This essay previously appeared on BoingBoing.

Posted on March 3, 2014 at 7:48 AMView Comments

A Really Good Article on How Easy it Is to Crack Passwords

Ars Technica gave three experts a 16,000-entry encrypted password file, and asked them to break them. The winner got 90% of them, the loser 62% — in a few hours.

The list of “plains,” as many crackers refer to deciphered hashes, contains the usual list of commonly used passcodes that are found in virtually every breach involving consumer websites. “123456,” “1234567,” and “password” are there, as is “letmein,” “Destiny21,” and “pizzapizza.” Passwords of this ilk are hopelessly weak. Despite the additional tweaking, “p@$$word,” “123456789j,” “letmein1!,” and “LETMEin3” are equally awful….

As big as the word lists that all three crackers in this article wielded — close to 1 billion strong in the case of Gosney and Steube — none of them contained “Coneyisland9/,” “momof3g8kids,” or the more than 10,000 other plains that were revealed with just a few hours of effort. So how did they do it? The short answer boils down to two variables: the website’s unfortunate and irresponsible use of MD5 and the use of non-randomized passwords by the account holders.

The article goes on to explain how dictionary attacks work, how well they do, and the sorts of passwords they find.

Steube was able to crack “momof3g8kids” because he had “momof3g” in his 111 million dict and “8kids” in a smaller dict.

“The combinator attack got it! It’s cool,” he said. Then referring to the oft-cited xkcd comic, he added: “This is an answer to the batteryhorsestaple thing.”

What was remarkable about all three cracking sessions were the types of plains that got revealed. They included passcodes such as “k1araj0hns0n,” “Sh1a-labe0uf,” “Apr!l221973,” “Qbesancon321,” “DG091101%,” “@Yourmom69,” “ilovetofunot,” “windermere2313,” “tmdmmj17,” and “BandGeek2014.” Also included in the list: “all of the lights” (yes, spaces are allowed on many sites), “i hate hackers,” “allineedislove,” “ilovemySister31,” “iloveyousomuch,” “Philippians4:13,” “Philippians4:6-7,” and “qeadzcwrsfxv1331.” “gonefishing1125” was another password Steube saw appear on his computer screen. Seconds after it was cracked, he noted, “You won’t ever find it using brute force.”

Great reading, but nothing theoretically new. Ars Technica wrote about this last year, and Joe Bonneau wrote an excellent commentary.

Password cracking can be evaluated on two nearly independent axes: power (the ability to check a large number of guesses quickly and cheaply using optimized software, GPUs, FPGAs, and so on) and efficiency (the ability to generate large lists of candidate passwords accurately ranked by real-world likelihood using sophisticated models).

I wrote about this same thing back in 2007. The news in 2013, such as it is, is that this kind of thing is getting easier faster than people think. Pretty much anything that can be remembered can be cracked.

If you need to memorize a password, I still stand by the Schneier scheme from 2008:

So if you want your password to be hard to guess, you should choose something that this process will miss. My advice is to take a sentence and turn it into a password. Something like “This little piggy went to market” might become “tlpWENT2m”. That nine-character password won’t be in anyone’s dictionary. Of course, don’t use this one, because I’ve written about it. Choose your own sentence — something personal.

Until this very moment, these passwords were still secure:

  • WIw7,mstmsritt… = When I was seven, my sister threw my stuffed rabbit in the toilet.
  • Wow…doestcst::amazon.cccooommm = Wow, does that couch smell terrible.
  • Ltime@go-inag~faaa! = Long time ago in a galaxy not far away at all.
  • uTVM,TPw55:utvm,tpwstillsecure = Until this very moment, these passwords were still secure.

You get the idea. Combine a personally memorable sentence, some personal memorable tricks to modify that sentence into a password, and create a long-length password.

Better, though, is to use random unmemorable alphanumeric passwords (with symbols, if the site will allow them), and a password manager like Password Safe to store them. (If anyone wants to port it to the Mac, iPhone, iPad, or Android, please contact me.) This article does a good job of explaining the same thing. David Pogue likes Dashlane, but doesn’t know if it’s secure.

In related news, Password Safe is a candidate for July’s project-of-the-month on SourceForge. Please vote for it.

EDITED TO ADD (6/7): As a commenter noted, none of this is useful advice if the site puts artificial limits on your password.

EDITED TO ADD (6/14): Various ports of Password Safe. I know nothing about them, nor can I vouch for their security.

Analysis of the xkcd scheme.

Posted on June 7, 2013 at 6:41 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.