Tag Archives: Cryptography

Recommended DD-WRT settings

I’ve been asked a few times now for my recommended DD-WRT settings, or at least my good-enough settings. I think that’s a great idea, so I’ll walk through how I configure a DD-WRT router. Follow these steps and I can almost guarantee you’ll have the most secure network on your block.

For the purposes of this tutorial, I am going to assume you are configuring DD-WRT as your primary router.

Continue reading Recommended DD-WRT settings

New password advice from GCHQ

The GCHQ is the British equivalent of the NSA. They recently published a new document containing the GCHQ’s new password advice in light of the things we’ve learned in the last few years. It’s worthwhile reading, whether you’re a sysadmin or a web developer or just an end user who wants to stay secure online.

Some of the advice may be surprising.

Continue reading New password advice from GCHQ

How to use the lock in your web browser’s location bar

A commenter asked me last week if I really believe the lock in a web browser means something.

I’ve configured and tested and reviewed hundreds of web servers over the years, so I certainly hope it does. I spend a lot more time looking at these connections from the server side, but it means I understand what I’m seeing when I look at it from the web browser too.

So here’s how to use it to verify your web connections are secure, if you want to go beyond the lock-good, broken-lock-bad mantra.

Continue reading How to use the lock in your web browser’s location bar

Steve Gibson on Truecrypt

Dan Bowman sent me this link to Steve Gibson’s analysis of Truecrypt, a suddenly dear departed piece of full disk encryption software.

The important thing to remember right now is that we still don’t know what’s going on.

Johns Hopkins cryptography professor Matthew Green is heading up an effort to audit the Truecrypt code. Last month he said the code could be of higher quality, but at that point he hadn’t found anything truly horrible in there either.

That said, his analysis of the cryptography itself is phase 2. Cryptography is notoriously difficult to do–even when cryptography is your specialty, you can get it wrong.

So it’s premature to declare Truecrypt 7.1 as the greatest piece of software ever written. Green did find some flaws that need to be fixed. As far as we know, right now Truecrypt is better than nothing, but the most important part of Green’s work isn’t finished yet. Green has said he is going to finish his audit of the code. He probably won’t find perfection. He may find a fatal flaw that makes it all come crashing down. More likely, he’ll find something in between. But until those findings come out, it’s all speculation.

In theory, someone else can come along, take the existing code, act on Green’s findings, and make it better. But that’s all still in an uncertain future. We don’t know yet what’s possible and we don’t know yet who’s interested in picking up the torch and running with it.

Gibson’s page on Truecrypt is a good reference page, but his cheerleading is premature. Gibson is a talented software developer in his own right, but cryptography isn’t his specialty. At the company where I work, we use Truecrypt for some things, and until we know otherwise we are going to continue to use it, but we haven’t made any final decisions on it yet.

Update: Here’s an analysis by Mark Piper, a penetration tester by trade, who explains the history and the issues today.

IT security vs. the construction industry

On the Risky Business podcast last week, Andrew Wilson, the CEO of Australian cryptography gear maker Senetas, stated that many businesses see the bad things that happen from poor IT security as just a cost of doing business.

Nothing revolutionary there. We’ve all seen it. Target is paying a steep price right now, but what about Michaels and Nieman Marcus? They got breached at the same time as Target, and nobody’s talking about them. Maybe Target thinks the cost of doing business got too high, and they’ve hired a CISO and I hear they’re hiring lots of new security personnel–I have coworkers and former coworkers in the Minneapolis area who tell me as much–but for Michaels and Nieman Marcus, the cost, at least so far, appears to have been manageable.

But Wilson added something that I hadn’t heard anywhere else before. Fifty years ago, he said, construction workers dying while building a large building was considered a cost of doing business. Fifty years ago that was normal. Today it’s unacceptable.

Continue reading IT security vs. the construction industry

Why last week’s “news” of the NSA’s quantum computer project doesn’t bother me

Last week, another Snowden leak surfaced that stated that the NSA is working on a quantum computer capable of breaking all known current encryption, trivially.

I didn’t find this shocking. Continue reading Why last week’s “news” of the NSA’s quantum computer project doesn’t bother me

Hostsman makes it easy to block malware with a hosts file

I’ve written before about using the hosts file to block domains that are hosting malware. The idea is pretty simple. There’s a known list of domains that are either hosting or controlling malware, so by blocking your computer from accessing those domains, you make it much harder to get infected in the first place, and in the event that you do get infected, at least you block access to the command and control servers.

The problem is that Windows doesn’t make this easy. Well, I found an easy way: Hostsman. You can have it up and running in minutes.

Continue reading Hostsman makes it easy to block malware with a hosts file

Why your favorite web site’s password strength meter is full of hooey

Ars Technica talked three password crackers into doing their worst to a leaked database of 16,000 passwords, to see what they could learn.

They learned a lot, and we can learn a lot from their experience as well. “qeadzcwrsfxv1331” isn’t a good password. Neither is “Philippians4:13.” Neither is “correcthorsebatterystaple.” Neither is “Qbesancon321” or “Qbe$@ncon321.” Password guessing has too much intelligence built into it now.

And not only that, by continuing to use the password “popcorn,” you make it easier for those guys to guess other passwords too. Continue reading Why your favorite web site’s password strength meter is full of hooey