I can hear the comments now: “Not a hack.” Yeah that might be true, but it’s still enormous puppets running around Berlin – that in its own right is pretty cool. The show, put on by the street theater group Royal De Luxe, is part of the 20th anniversary for the fall of the Berlin Wall. Spectators watched as the Big Giant rose from the water in search of his niece, the Little Giantess. We won’t spoil the ending, but its a happy one. Reminds us of the similar giant marionette group La Machine, and their La Princesse.

This past weekend, Berlin played host to Music Hack Day – an event where attendants built and tested hacks, contraptions, and software all dealing with sound, music, or the distribution thereof. Some of the hacks are simply mind blowing to see built in only a day or two. Like the location based CitySounds.fm or Tracks on a Map – mapping out where your music is from. Or the music based games and composition tools, iLoveAcid squencer and MaschineFighter – adding some crazy fun to MIDI.

Oh, we almost forgot, we can’t go an entire post without mentioning something Arduino; named Xylobot – a set of servos powered by Arduino, tapping out rhythm on a xylophone (video above). Another Hack Day is planned so keep an eye out.

[Thanks robb]

A team of security researchers and academics has broken a core piece of internet technology. They made their work public at the 25th Chaos Communication Congress in Berlin today. The team was able to create a rogue certificate authority and use it to issue valid SSL certificates for any site they want. The user would have no indication that their HTTPS connection was being monitored/modified.

This attack is possible because of a flaw in MD5. MD5 is a hashing algorithm; each unique file has a unique hash. In 2004, a team of Chinese researchers demonstrated creating two different files that had the same MD5 hash. In 2007, another team showed theoretical attacks that took advantage of these collisions. The team focused on SSL certificates signed with MD5 for their exploit.

The first step was doing some broad scans to see what certificate authorities (CA) were issuing MD5 signed certs. They collected 30K certs from Firefox trusted CAs. 9K of them were MD5 signed. 97% of those came from RapidSSL.

Having selected their target, the team needed to generate their rogue certificate to transfer the signature to. They employed the processing power of 200 Playstation 3s to get the job done. For this task, it’s the equivalent of 8000 standard CPU cores or $20K of Amazon EC2 time. The task takes ~1-2 days to calculate. The tricky part was knowing the content of the certificate that would be issued by RapidSSL. They needed to predict two variables: the serial number and the timestamp. RapidSSL’s serial numbers were all sequential. From testing, they knew that RapidSSL would always sign six seconds after the order was acknowledged. Knowing these two facts they were able to generate a certificate in advance and then purchase the exact certificate they wanted. They’d purchase certificates to advance the serial number and then buy on the exact time they calculated.

The cert was issued to their particular domain, but since they controlled the content, they changed the flags to make themselves an intermediate certificate authority. That gave them authority to issue any certificate they wanted. All of these ‘valid’ certs were signed using SHA-1.

If you set your clock back to before August 2004, you can try out their live demo site. This time is just a security measure for the example and this would work identically with a certificate that hasn’t expired. There’s a project site and a much more detailed writeup than this.

To fix this vulnerability, all CAs are now using SHA-1 for signing and Microsoft and Firefox will be blacklisting the team’s rogue CA in their browser products.

Capture the Flag (CTF) is a long running tradition at hacker conventions. It pits teams of security researchers against each other on the same network. Every team gets an identical virtual machine image. The VM has a set of custom written services that are known to be vulnerable. The teams work to secure their image while simultaneously exploiting services on the machines of other teams. A scoring server monitors the match as it progresses and awards points to teams for keeping their services up and also for stealing data from their competitors.

The Chaos Communication Congress in Berlin December 27-30, 2008 will host a CTF competition. Most CTF matches are done head to head in the same room. While 25C3 will have local teams, it will also be wide open for international teams to compete remotely. Remote teams will host their own images on a VPN with the other competitors. Now is a good time to register and familiarize yourself with the scoring system. It will certainly be interesting to see how this competition plays out now that teams that can’t make the trip can still compete.

The team behind 25C3 has published the first draft of this year’s schedule. The annual Chaos Communication Congress is happening December 27th to 30th in Berlin, Germany. There are plenty of interesting talks already in place. We’re spotting things we want to attend already: The conference starts off with how to solar power your gear, which is followed by open source power line communication. A TOR-based VPN, an open source BIOS, rapid prototyping, holographic techniques, and running your own GSM network are on the bill too.

We’ll have at least three Hack a Day contributors in attendance. Last year featured two of our favorite conference talks: [Drew Endy]‘s Biohacking and the MiFare crypto1 RFID crack. We hope to see you there.

[photo: mark]

[via BoingBoing]