When your browser throws a security warning, do you feel a bit uneasy? Even if you have every reason to believe that the site is safe? Let’s assume that you (like most people) do. You certainly don't want your business partners, customers, or employees to have any doubts about the safety of one of your organization's sites. Unfortunately, it could already be happening.
Sure, there’s a good reason why popular browsers such as Internet Explorer (IE), Chrome, and FireFox are warning users away from a large number of seemingly legitimate sites. These sites are secured by digital certificates that are signed with the outdated (i.e. vulnerable) SHA-1 cryptographic hash algorithm.
SHA-1 certificates are vulnerable to attack
Way back in January 2011, the National Institute of Standards and Technology (NIST) forewarned organizations of SHA-1's vulnerability. In the years that have passed since that warning, CAs and browser vendors have been coming to terms with the agonizingly slow death of that algorithm. Meanwhile, Venafi has been helping organizations prepare for the eventual demise by locating and replacing certificates that use SHA-1.
But in late 2015, researchers discovered that a successful SHA-1 collision attack could be done for as little as $75,000. Now that these attacks have become affordable, browser vendors are upping their game, actively warning users that sites secured with SHA-1 are not necessarily secure. They then plan to begin outright rejecting SSL certificates that use SHA-1 in early 2017 (Mozilla and Google plan to start rejecting access to sites with SHA-1 certificates as of January 1, 2017, while Microsoft IE and Edge will block sites using SHA-1 as of February 14, 2017) . Mozilla even considered ending support for SHA-1 certificates in Firefox as of January 2016, but reconsidered after evaluating the impact on users.
How safe is your business from a SHA-1 exploit?
If you are assuming that your organization has already moved away from SHA-1 to SHA-2 or SHA-3, you may want to check with your IT staff to be sure. Surprisingly, the SSL Pulse Project, which surveys the SSL implementations of the world's most visited websites, found in October 2015 that 24% of 143,000 popular sites were still using SHA-1 certificates. And here at Venafi, we’ve found that many global enterprises are still struggling with their SHA-1 migration. The odds are pretty good that at least some of your organization's sites—and probably some of its applications, too—still use SHA-1.
This observation isn't meant to belittle your hard-working IT staff's judgment or motivation. Migrating from SHA-1 to a more secure algorithm isn’t as straightforward as it would seem. For one thing, enterprises typically have multiple thousands of certificates to manage. For another, some legacy applications simply don't support SHA-2 or SHA 3.
What’s the real impact of a stalled SHA-1 migration?
Despite the difficulty factor, your organization must complete the migration as soon as possible. This issue is bigger than just a warning in a browser address bar that gives a negative perception of your organization's trustworthiness (although this is enough—no business wants to lose customer confidence).
An even bigger concern is that SHA-1 leaves your organization vulnerable to breaches and non-compliance fines, both of which are immediately destructive. Of course, breaches and fines do have a way of inevitably circling back to further tarnish your organization's reputation as well.
Given these looming consequences, if you haven't already started your migration to SHA-2 or SHA-3, ask yourself—what are you waiting for? It’s late to start now. But not too late.