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How I cracked my neighbor's WiFi password without breaking a sweat

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Re: How I cracked my neighbor's WiFi password without breaking a sweat

#131

Post by Nikker »

scott_s wrote: post #51
Xurinos wrote: post #45

Earlier quoted context omitted.

One should change passwords on an irregular basis (a regular basis is weaker protection than an irregular basis). This is just an additional layer of security, not a perfection. If the password has ever been compromised, a password change policy removes the key from bad hands. Discovered passwords are not always immediately used; in many situations, they are stored for later use, perhaps even sold/traded.

We shouldn't make such proclamations based on reasoning along. Security policy that involves human behavior depends extensively on what humans do . So while a particular security policy may be the safest, most rational thing to do, it may fail in practice if people execute it poorly. So, if it is true that when people regularly change their passwords, they pick poorer passwords, then perhaps those poor passwords are…

Cryptography in it's own principals are based on probability. If ignoring physical access attacks, social engineering attacks, etc are acceptable to you then yes, you can keep a "good" password for a long time. You also have to accept that out of all possible attacks accounting for nothing but brute force and basic dictionary attacks is 'enough' then you should also acknowledge the risks.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#132

Post by icebraining »

laxk wrote: post #81

Is there way to measure WiFi signal quality between router and connected devices? any API on linux side? An easy generic protection can be done in the following way (if there is api): Ban all unknown MAC addresses with WiFi signal quality below the specific treshhold. In that case if hacker decides to use fake MAC address he cannot fake signal quality on my side. Does it work?

You can measure the signal quality, but that doesn't buy you much. If you only ban unknown MACs, then he can just clone yours, and signal quality is easy to evade with a cheap (In my home, I often get a better signal using my laptop with an external antenna two walls from the AP than with my phone just a couple of meters away from it.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#133

Post by phaemon »

eric_bullington wrote: post #113
lotharbot wrote: post #102

Earlier quoted context omitted.

> "Are you seriously arguing that "The quick brown fox Jumps over the lazy dog!" is less human-memorable than "dlLejs$sAgkCnzklS%9sxckAAnvk"?" I didn't say "password", I said "passphrase". Something like "breath red long provide" or "itself even willing establish". If you're using memorable movie quotes or Shakespeare quotes or anything else that you could find on wikiquote, your keyspace is going to be smaller than…

Or if you're on Linux: shuf -n4 /usr/share/dict/words | tr -d '\n'; echo

Actually, just:

echo $(shuf -n4 /usr/share/dict/words)

will do the trick. Though it does have some weird words in there. A trimmed "4000 common words" dictionary is what I use.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#134

Post by caspianm »

jdthomas wrote: post #80
mgualt wrote: post #44

A couple of naive questions about the design of the security system: 1. Why is it possible to do the password tests remotely? Why would the key on the router be allowed to be transmitted? Even a 6 character password should be safe if you don't allow multiple tries. 2. Why isn't the handshake protocol encrypted?

1. The attack is to brute force the shared secret (password). This can be done offline because by capturing the exchange you have the ANonce and SNonce and all other information required to generate the same key -- except the shared secret. Try lots of passwords and check if you generate the same PTK as the two stations do. 2. Encrypted with what? This is the key exchange stage that is attacked here. 802.11w adds sig…

Password authenticated key exchange should do what we want. I was hoping WPA2 would have have used it already.

http://en.wikipedia.org/wiki/Password-authenticated_key_agre...

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#135

Post by scott_s »

Nikker wrote: post #131
scott_s wrote: post #51

Earlier quoted context omitted.

We shouldn't make such proclamations based on reasoning along. Security policy that involves human behavior depends extensively on what humans do . So while a particular security policy may be the safest, most rational thing to do, it may fail in practice if people execute it poorly. So, if it is true that when people regularly change their passwords, they pick poorer passwords, then perhaps those poor passwords are…

Cryptography in it's own principals are based on probability. If ignoring physical access attacks, social engineering attacks, etc are acceptable to you then yes, you can keep a "good" password for a long time. You also have to accept that out of all possible attacks accounting for nothing but brute force and basic dictionary attacks is 'enough' then you should also acknowledge the risks.

I think you're missing my key point: you have to compare two different risks, based on observation. The first risk is the risk of continuing to use a compromised password. The second risk is the risk of users introducing weaker passwords because they continually change them. We can use our reasoning to come up with a decent probability for the first risk. We cannot do so for the second risk, since it depends on how people behave. We must study people to assign a number to the second risk.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#136

Post by mikle »

forcer wrote: post #38
mikle wrote: post #34

Earlier quoted context omitted.

I want to add to mock's point - I will trust you more if I could download it from your site than from download.com. It has become such a dump that I actively avoid visiting it. Why delegate the user experience of downloading your products to someone whose interests don't align with yours?

OK. Point taken. We have done some A/B tests and see that download rate is the same as from our website. The benefit of redirecting to download.com is that with increased rankings we get more users who visit download.com. I know these issues you said and I saw the articles on HN before. However, you can tell download.com to stop injecting offers into the installer which we did and there are no issues.

Well my point wasn't about the installer (although it is too a good point). I'm mostly talking about the UI and UX benefits of having a streamlined experience of downloading a product.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#137

Post by Dylan16807 »

ctdonath wrote: post #115
Dylan16807 wrote: post #101

Earlier quoted context omitted.

>network sniffing hardware a large fraction of normal wifi devices that can be set into a proper receiving mode >sophisticated password guessing tools some password cracker they downloaded in minutes >hours of planning pressing a button or typing a couple commands >and execution taking a nap It's not hard to secure a network from extremely simple attacks. At least for now. And that analogy is nonsense. Body armor, ni…

The analogy is fine. Walk into a well stocked military surplus store and you can walk out with all the tools you need to break into a house in short order, and trust me it doesn't take long to learn how to use them well enough. The point is that once someone is determined enough to get into either your home or network, it doesn't take much to reach a stage where the owner has to go to great lengths to resist a very u…

My point is that you don't need any tools to break into a house. Kick in a door or throw a rock through a window. That is why the analogy is bad. Someone has to be very determined at breaking in to buy all those things. Someone has to be very determined to break into a secured network.

But someone does not have to be determined to break into the average house. And they do not have to be determined to break into a network that is misconfigured.

Using WPA2 with a long password and turning off WDS makes a network safe from direct attack.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#138

Post by lotharbot »

commandar wrote: post #129
lotharbot wrote: post #124

Earlier quoted context omitted.

My line of argument is more complex than you give it credit for. It has 3 major components: - if you do not include "unique elements" (that is, you quote straight from wikiquote or similar), a quote is less secure than 4 random dictionary words due to being subject to wikiquote-driven dictionary-style attacks. - if you include intentional and unique modifications, a quote from a public work like a movie or play is no…

>then your passphrase is vulnerable to a dictionary-like attack by an attacker who has some knowledge of you, particularly one who you've told your scheme to. That's the thing right there: the difference in practical vulnerability all but requires an attacker to have a certain level of omniscience and access to a massive database of any conceivable permutation of any fragment you might choose of a huge number of work…

On the one hand, you're saying that it's a huge keyspace because you might choose from such a huge number of works and there are so many possible variations. My criticism of that version of your idea is that those variations are as hard to remember as random words.

On the other hand, you're telling people "use a sentence from something you like", which is likely to result in only the smallest exploration of that keyspace -- the most popular lines out of the most popular shows or movies, with only a small number of capitalization or punctuation variants. If people are going to pick things like "to be or not to be" or "I can kill you with my brain", then you're suggesting something that's not particularly secure (and may already be contained in many dictionary attacks).

So the approach you advocate is fundamentally insecure, which you've argued can be made secure by adding exactly the sort of measures that confuse the issue for the people you say will benefit from the approach.

Here's an easier approach: tell people "anything you can find in a dictionary or on a list of quotes, hackers already have on their computers. To make a password hackers don't already know about, you need to put some random words together." Then point them to passphra.se and tell them to hit "generate another" until they get something they like. They can even add in more words to make it more memorable, or mix their random words into a movie quote ("I can melt you with my smoky vegetable universe", in River Tam's voice... creepy and memorable.)

In other words, instead of starting with "memorable" and then trying (and probably failing) to add enough entropy without sacrificing memorability, start with enough entropy and then make it memorable.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#139

Post by frankus »

robertskmiles wrote: post #88
frankus wrote: post #70

My strategy is to use a human-readable password for my guest network (which I actually considered leaving completely open), and a crazy-long random password that I copy and paste from my password manager for my internal network.

Why did you decide not to leave it open?

I felt like it would make me responsible for monitoring it for abuse.

It could be something as innocent as a cheapskate neighbor using enough bandwidth to run afoul of my cap, or someone using it for nefarious purposes either on a continuous or drive-by basis.

Re: How I cracked my neighbor's WiFi password without breaking a sweat

#140

Post by Nikker »

scott_s wrote: post #135
Nikker wrote: post #131

Earlier quoted context omitted.

Cryptography in it's own principals are based on probability. If ignoring physical access attacks, social engineering attacks, etc are acceptable to you then yes, you can keep a "good" password for a long time. You also have to accept that out of all possible attacks accounting for nothing but brute force and basic dictionary attacks is 'enough' then you should also acknowledge the risks.

I think you're missing my key point: you have to compare two different risks, based on observation. The first risk is the risk of continuing to use a compromised password. The second risk is the risk of users introducing weaker passwords because they continually change them. We can use our reasoning to come up with a decent probability for the first risk. We cannot do so for the second risk, since it depends on how p…

I think I see your point but you have to admit you haven't really established a foundation for your argument. You seem to feel (and I may be wrong of course) that one person selecting a fairly secure pass phrase once would be much more secure at any single point in time rather than a hap-hazard, dictionary based pass phrase that in comparison would be likely trivial to compromise at that same point of time. If that is indeed your point you do convey a valid point.

I just ask that if you advertise this method as somehow ideal then please allow for your audience to appreciate it as it is, an "if all else fails it's better than nothing" approach.

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