Web Encryption’s Coming Crisis

As bad as 2014 was, 2015 managed to actually be worse for data security and has been rife with breaches, including the big one at Anthem that left between one-third and one-half of all American’s personal information exposed.

The Internet didn’t need new security problems for Christmas; it already had plenty. But the tireless efforts of criminal hackers and the professional crime syndicates that hire them are the unwanted gift that keeps on giving, and it is looking alarmingly clear that very soon they might just have a lot more to “offer” us all.

Why?

Because the cryptographic algorithm known as “SHA-1” is apparently dangerously close to being completely compromised by hackers. And while that may sound like a somewhat abstract issue to anyone who is not already a programmer or developer, the outcome for a widespread break in SHA-1 would not be abstract.

A successfully broken SHA-1 in the wild would give hackers easy access to a host of password-protected systems, the ability to create fake banking and payments sites that would look legitimate to users (and their computer’s security protections) or a direct path for placing malware into seemingly innocent computer system updates. Or some combination of those — or any number of other horrible effects.

The potential for chaos via the SHA-1 instability is not new information; Google already warns users when it is in play on the Web, and by July 2016, Google, Mozilla and Microsoft will all have pulled the plug on their support for the algorithm. But that is a new date. The previous deadline had been 2017, but all three have decided to push up the due date because it looks like SHA-1 might be a bit more breakable than previously thought — and much more in peril.

So, What Does SHA-1 Do?

Said simply, SHA-1 is a hashing algorithm, which means it inputs meaningful data and outputs that data as a mishmash of letters and numbers, called a hash, that is impossible to read. Unlike standard encryption, which is a two-way function — meaning data is turned into nonsense at one end of the chain and then translated back into usable material at the other end — hashing is a one-way ride. Hashes are designed specifically with the intention of making it impossible to use the output (the hash) to reverse-engineer the input.

Hashes have a variety of uses. Passwords are generally hashed data — a user inputs the password the first time, at which point the system’s hashing algorithms turn it into data soup that the email platform then stores. Because every data input has one (and only one) possible hash and changing the input in any way changes the hash, it is a good way to store a password. Even if the system gets hacked, thieves end up with unusable hashes and no way to generate the original password from them.

The other common use for hashing — and the use SHA-1 is most often put toward — is issuing for securing digital certificates for Web browsing in secured sessions. And those digital certificates are extremely important because they are the go-to tool in securing browsing sessions and making sure that the banking or commerce website you think you are on is actually that website and not a particularly convincing copy of it designed to steal your login information upon entry.

According to reporting on Motherboard, as of October of this year, SHA-1 was used for more than 28 percent of digital certificates.

SHA-1 Is Totally Beatable — Now On The Cheap

The hack for hashing functions is a collision attack, which essentially makes it possible for two totally different inputs to create the same hash. Mostly, they are carried out by brute force; cyberattackers aren’t trying to outthink or break the hash so much as they are throwing computing power against it and leveraging brute force to break through.

The risks posed by SHA-1’s susceptibility to collision attacks have been known since 2012 when Intel employee Jesse Walker estimated that an attack on SHA-1 could be successfully financed for a cost of about $2.77 million. And that, he noted, is essentially paying bust-out retail, so to speak, as the pricing would only get more and more affordable, costing $700,000 by 2015 and as little as $43,000 by 2021. Even at the top price point, the attacks are not entirely unaffordable for many criminal enterprises, and at the bottom, it is darn near a bargain, considering the value of the data at stake.

And those numbers might be something of an overestimation. A paper by researchers this year indicated that even those cost estimates might be inflated and that particularly enterprising and budget-conscious thieves could break SHA-1 by leveraging typical computer graphics cards (as opposed to more costly server banks).

“We just successfully broke the full inner layer of SHA-1. We now think that the state-of-the-art attack on full SHA-1 as described in 2013 may cost around $100,000 renting graphics cards in the cloud,” Marc Stevens, a cryptographer who worked on the research, said in a press release published at the time.

Other hashing algorithms — MD5, for example — have been brought down in a similar fashion. In 2008, researchers fully broke that system using 200 PlayStation 3 consoles and $700 in test certificates. Malicous uses of MD5 included nation-state hackers using it to generate “Microsoft” certificates that were fake, hard to detect and that gave them access to millions of computers.

Time To Say Goodbye

As researchers are increasingly convinced that it will not only soon be possible but highly cost-effective to go after SHA-1, we see the mass exodus away from the algorithm by the world’s biggest browsers and the concerted effort to get everyone in on that changeover as soon as possible.

As of Jan. 2016, Chrome will display a warning if a site is signed with an SHA-1-based signature; by July, it will not connect at all to sites that use it, Google noted in a recent blog post.

And while that move away is good news, it does leave the simple fact that once SHA-1 is gone, those criminal hackers will turn to the hashing algorithms that replace it and begin working on finding the fastest and cheapest way to burn those to the ground. After all, SHA-1 was once the more secure option offered over MD5.

Stay tuned.