Looking Forward To SHA2017

We’re at the start of August, which can only mean one thing. Europe’s hackers and makers are about to converge in a field somewhere for a long weekend of sitting around drinking beer and Club-Mate, eating unhealthy street food, being assaulted by some of the most underground chiptune electronic dance music on the planet, sharing the fruits of their labours with their peers, and gazing lovingly upon other people’s hacks. This year it’s the turn of the Netherlands, for over the first full weekend in August that country will host the SHA2017 outdoor hacker camp in a scouting camp on the polders. It promises to be quite an event, with just short of 4000 attendees spread over several fields, arenas, and social areas, and we’re going to be there. Tent and power lead with Schuko plug sorted, massive pile of stickers secured, DECT phone charged, emergency supplies of PG Tips packed.

There is so much to take in at these events that it can sometimes be difficult to catch everything. One can do the rounds as diligently as possible and still miss some of the cool stuff, so this is where you come in. Are you going to SHA? Are you bringing anything you consider cool to the event? Tell us about it in the comments, we’d love to hear about it as would we’re sure the rest of our readers.

Meanwhile, if you think you’ve missed the boat, don’t panic! At the time of writing, there are about 180 tickets still unsold, but they’ll be going fast! Head over to the SHA2017 tickets site to get yours.

(The stripey header, in case you were wondering, is SHA2017’s branding using as you might have guessed, the SHA algorithm to generate HTML colours. What you see are the colours for “Hackaday”.)

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.

25C3: Hackers completely break SSL using 200 PS3s

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.

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ToorCon 9: Crypto Boot Camp

[Rodney Thayer] gave a 2 hour seminar on cryptographic technology. It was designed to give the audience a working knowledge for dealing with vendors. He gave some rules of thumb for choosing encryption. In order of preference, when doing symmetric key crypto: use AES with a minimum 128bit key, if not that 3-key Triple-DES, or last RC4 with 128bit key. For hashing: SHA 256 preferred, SHA 1 if you can’t do any better, and MD5 if you can’t SHA. For public key: RSA using at least a 2048bit key. The top choices in these lists were picked because they’ve stood up to years of scrutiny. One major theme of talk was to never roll your own crypto algorithm or buy someone elses. Proprietary algorithms get broken all the time, like the GSM A5 crypto we talked about earlier this year.