Inconvenient Message Detection



Steganography that requires computing effort. Steganography is the idea of hiding data in the unimportant bits of an image. This is an old idea. The new twist is that with ‘Inconvenient Message Detection’ (IMD) that data can only be found if the decoder does an amount of computational work that’s decided by the encoder.

Let’s look at how this solved our problem: If some people use IMD, it makes every image suspect. When a mass-observer wants to see what communication is going on, they must use compute power to check every image. Furthermore, because the compute effort needed to find an image is set by the encoder, it is uncertain to the mass-observer; they never knows for certain if they’ve worked hard enough. By contrast, the intended recipient of a message presumably got the single datum that a message exists in some public image and will put in as much compute effort as is needed to find the data in that single image. Having every image on the internet be a potential carrier of secrets makes the mass observation of communication meta-data expensive and uncertain.

Furthermore, even a individual under direct observation can increase their protection with IMD. An individual may own thousands of images of which only one contains an secret. Until the secret is found by an observer, the individual has plausible denyability of the secret’s existence. The observer may even give up before spending the necessary compute effort to find it. This increases their resistance to coercion. · Grass Mud Horse


The Chinese government is not only being deceitful with IP addresses, they’ve also begun cracking down on a mechanism that lets its citizens avoid the bullshit: VPN. Grass Mud Horse!

This action, combined with the DDoS floods, is beneficial to a government that’s intent on isolating its citizens from the free and open Internet. They make it hard to get a packet out of China, but even if you succeed, it’s likely to be blocked by a server that’s been victim of their DDoS.

On the surface, this seems like a good strategy for creating your own private Internet: a network where no packets can enter the west or leave the east.

via · Grass Mud Horse.

I’ve been seeing a lot of probes in my logs — mostly search engines, but a fair bit that wasn’t — from China. And here you go.

Newly published NSA documents show agency could grab all Skype traffic | Ars Technica


The full capture of voice traffic began in February of 2011 for “Skype in” and “Skype out” calls—calls between a Skype user and a land line or cellphone through a gateway to the public switched telephone network (PSTN), captured through warranted taps into Microsoft’s gateways. But in July of 2011, the NSA added the capability of capturing peer-to-peer Skype communications—meaning that the NSA gained the ability to capture peer-to-peer traffic and decrypt it using keys provided by Microsoft through the PRISM warrant request.

via Newly published NSA documents show agency could grab all Skype traffic | Ars Technica.

An Unprecedented Look at Stuxnet, the World’s First Digital Weapon | WIRED


Don’t run “strings” against files…



Many shell users, and certainly most of the people working in computer forensics or other fields of information security, have a habit of running/usr/bin/strings on binary files originating from the Internet. Their understanding is that the tool simply scans the file for runs of printable characters and dumps them to stdout – something that is very unlikely to put you at any risk.

It is much less known that the Linux version of strings is an integral part of GNU binutils, a suite of tools that specializes in the manipulation of several dozen executable formats using a bundled library called libbfd.

Other well-known utilities in that suite include objdump and readelf.Perhaps simply by the virtue of being a part of that bundle, the strings utility tries to leverage the common libbfd infrastructure to detect supported executable formats and “optimize” the process by extracting text only from specific sections of the file. Unfortunately, the underlying library can be hardly described as safe: a quick pass with afl (and probably with any other competent fuzzer) quickly reveals a range of troubling and likely exploitable out-of-bounds crashes due to very limited range checking

Check the site for POC code. It’s old and it’s nasty.

Categories : Security

Google Online Security Blog: This POODLE bites: exploiting the SSL 3.0 fallback


With This Tiny Box, You Can Anonymize Everything You Do Online | WIRED

Categories : News  News  Privacy  Security

Holder urges tech companies to leave device backdoors open for police – The Washington Post


Attorney General Eric H. Holder Jr. said on Tuesday that new forms of encryption capable of locking law enforcement officials out of popular electronic devices imperil investigations of kidnappers and sexual predators, putting children at increased risk.

via Holder urges tech companies to leave device backdoors open for police – The Washington Post.


TL;DR: “we need to snoop on everything, for the kids”. Shameless, spineless, embarassing.

Categories : News  News  Privacy

Cory Doctrow on the need for easy to use security mechanisms


Cory Doctrow via The Guardian:

Technical people need our non-technical friends to adopt good privacy practices. Every communications session has at least two parties, the sender and the recipient(s), and your privacy can leak out of either end of the wire. It doesn’t matter if I keep all my email offline, encrypted on my laptop, if it all ends up in the inboxes of people who leave it sitting on Gmail’s servers.

So this is critical, and not just for “normal people”. Even technically sophisticated people often find it difficult to follow security protocol in their own communications and computing. Things that aren’t usable just don’t get used. Making crypto as easy as your favourite websites and apps is the only way to make privacy a reality for everyone.

via Privacy technology everyone can use would make us all more secure | Technology |


That’s all well and good, but how do you do it? If you’re reading this, it’s a safe bet you’re at least interested in the idea of data security. But how do you implement this among the nontechnical? It’s easy enough to tell a group of technical people “install PGP, encrypt and sign everything, don’t use weak keys” etc. But how do you get your mom to use it? Or the 62-year-old accountant that prefers to not have to deal with computers except to buy things online and email old friends or distant relatives?

Categories : News  Security

A Few Thoughts on Cryptographic Engineering: What’s the matter with PGP?


A Few Thoughts on Cryptographic Engineering: What’s the matter with PGP?.

TL;DR: keys suck, key management sucks, no perfect foward secrecy really sucks, implementation sucks, software sucks and we should rethink how to do this stuff slightly better.

If you’ve used PGP (or GPG), it’s hard to find fault with his arguments, though.

Categories : Security