SHAttered — SHA-1 is broken in

A team from Google and CWI Amsterdam just announced it: they produced the first SHA-1 hash collision. The attack required over 9,223,372,036,854,775,808 SHA-1 computations, the equivalent processing power as 6,500 years of single-CPU computations and 110 years of single-GPU computations. While this may seem overwhelming, this is a practical attack if you are, lets say, a state-sponsored attacker. Or if you control a large enough botnet. Or if you are just able to spend some serious money on cloud computing. It’s doable. Make no mistake, this is not a brute-force attack, that would take around 12,000,000 single-GPU years to complete.

SHA-1 is a 160bit standard cryptographic hash function that is used for digital signatures and file integrity verification in a wide range of applications, such as digital certificates, PGP/GPG signatures, software updates, backup systems and so forth. It was, a long time ago, proposed as a safe alternative to MD5, known to be faulty since 1996. In 2004 it was shown that MD5 is not collision-resistant and not suitable for applications like SSL certificates or digital signatures. In 2008, a team of researchers demonstrated how to break SSL based on MD5, using 200 Playstations 3.

Early since 2005 theoretical attacks against SHA-1 were known. In 2015 an attack on full SHA-1 was demonstrated (baptized the SHAppening). While this did not directly translate into a collision on the full SHA-1 hash function due to some technical aspects, it undermined the security claims for SHA-1. With this new attack, dubbed SHAttered, the team demonstrated a practical attack on the SHA-1 algorithm, producing two different PDF files with the same checksum.

The full working code will be released in three months, following Google’s vulnerability disclosure policy, and it will allow anyone to create a pair of PDFs that hash to the same SHA-1 sum given two distinct images and some, not yet specified, pre-conditions.

For now, recommendations are to start using SHA-256 or SHA-3 on your software. Chrome browser already warns if a website has SHA-1 certificate, Firefox and the rest of the browsers will surely follow. Meanwhile, as always, tougher times are ahead for legacy systems and IoT like devices.

Hat Hash Hacking at DEFCON

You probably remember that for DEFCON I built a hat that was turned into a game. In addition to scrolling messages on an LED marquee there was a WiFi router hidden inside the hat. Get on the AP, load any webpage, and you would be confronted with a scoreboard, as well as a list of usernames and their accompanying password hashes. Crack a hash and you can put yourself on the scoreboard as well as push custom messages to the hat itself.

Choosing the complexity of these password hashes was quite a challenge. How do you make them hackable without being so simple that they would be immediately cracked? I suppose I did okay with this because one hacker (who prefers not to be named) caught me literally on my way out of the conference for the last time. He had snagged the hashes earlier in the weekend and worked feverishly to crack the code. More details on the process are available after the jump.

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DEFCON Shenanigans: Hack the Hackaday Hat

We don’t want to call it a challenge because we fear the regulars at DEFCON can turn our piece of hardware into a smoking pile of slag, but we are planning to bring a bit of fun along with us. I’ll be wearing this classy headgear and I invite you to hack your way into the WiFi enabled Hackaday Hat.

I’ll be wearing the hat-of-many-scrolling-colors around all weekend for DEFCON 22, August 7-10th in Las Vegas. You may also find [Brian Benchoff] sporting the accessory at times. Either way, come up and say hello. We want to see any hardware you have to show us, and we’ll shower you with a bit of swag.

Don’t let it end there. Whip out your favorite pen-testing distro and hack into the hat’s access point. From there the router will serve up more information on how to hack into one of the shell accounts. Own an account and you can leave your alias for the scoreboard as well as push your own custom message to the hat’s 32×7 RGB LED marquee.

You can learn a bit more about the hat’s hardware on this project page. But as usual I’ve built this with a tight deadline and am still trying to populate all the details of the project.

A Bitcoin mining example for the BeagleBone with an FPGA shield


If you’ve got a BeagleBone and an FPGA board you should give this Bitcoin mining rig a try. The hardware uses brute-force to solve hashes, looking for the rare sets that can be used as digital currency. This particular example is designed for the LOGi-bone which is an FPGA shield for the BeagleBone. But we don’t see anything that would make this difficult to use with other FPGA hardware.

We’ve seen FPGA hardware bitcoin mining in the past. It doesn’t offer as much horsepower as an array of GPUs would, but the ARM/FPGA combo can be used in a cluster in order to speed up the process. This sounds like a fun group project to take on at the local Hackerspace.

25 GPUs brute force 348 billion hashes per second to crack your passwords

It’s our understanding that the video game industry has long been a driving force in new and better graphics processing hardware. But they’re not the only benefactors to these advances. As we’ve heard before, a graphics processing unit is uniquely qualified to process encryption hashes quickly (we’ve seen this with bitcoin mining). This project strings together 25 GPU cards in 5 servers to form a super fast brute force attack. It’s so fast that the actual specs are beyond our comprehension. How can one understand 348 billion hashes per second?

The testing was used on a collection of password hashes using LM and NTLM protocols. The NTLM is a bit stronger and fared better than the LM, but that’s not actually saying much. An eight character NTLM password will fall in 5.5 hours, while a 14 character LM hash makes it only about six minutes before the solution is discovered. Of course this type of hardware is only good if you have a copy of the password hashes themselves. Login protocols will lock out after a certain number of attempts and have measures in place to slow down automated systems like this one.

[via Boing Boing]

GPU password cracking made easy

The power that a Graphics Processing Unit presents can be harnessed to do some dirty work when trying to crack passwords. [Vijay] took a look at some of the options out there for cracking passwords and found that utilizing the GPU produces the correct password in a fraction of the time. On a Windows machine he pitted the Cain password recovery tool which uses the CPU for its calculations against ighashgpu which uses ATI or Nvidia graphics cards to do the deed. Hands down ighashgpu is the fastest; with Cain taking about one year to crack an eight character password while ighashgpu can do it in under nineteen hours.

We were very interested to see how easy it is to use this package. We looked in on GPU cracking in September but didn’t focus on the software packages that are out there. Now that you know how easily your password can be unearthed perhaps you will get some use out of this article discussing the usability and security of longer passwords which we ran across over on Reddit.

Password exploitation classes online

open sesame is hosting an online class on password exploitation. The event was a fundraiser called ShoeCon, but they are hosting the entire series for everyone to share. Not only are the videos there, but you can download the powerpoint slides as well. There is a massive amount of information here on various topics like Hashcat, OCLHashcat, Cain, SAMDump2, Nir’s Password Recovery Tools, Password Renew, Backtrack 4 R1, UBCD4Win. There’s so much info, they split it into 3 sections. The videos are fairly long, between 1 and 2.5 hours each. What might surprise people is the amount of time that google is actually one of the main tools.

These videos can be a fantastic resource for hobby hackers, IT admins, and security professionals.