Threat Post reports on how browser developers are working on both adding support for as well as adding warnings into browsers for users that use less secure certificates signed by SHA-1 hashes. As computers continue to increase in performance it becomes easier, faster, and cheaper to break older hash algorithms. New algorithms get developed but are not always adopted quickly by software makers and certificate issuers.
In this case it is expected to become significantly more economically viable to break SHA-1 hashes via collision attacks. Collision attacks are where repeated tests occur looking for cases where more than one input produces the same output – since a hash accepts any length of input but a limited number of characters of output there will always be collisions – just a matter of how long it takes a computer to find those collisions. In most cases new and sophisticated hashing algorithms would take computers thousands if not millions of years to successfully find enough collisions to be usable, but as computers become faster it takes less time to crack the same algorithm. Once the algorithm becomes economically feasible to crack it is replaced and retired.
In 2012, Bruce Schneier projected a collision attack SHA-1 would cost $700,000 to perform by 2015 and $143,000 by 2018.
The Mozilla Firefox browser is expected to be the first browser to alert users of insecure certificates in just a few days (January 24, 2017). As more browsers are expected to adopt SHA-2 and warn about SHA-1 usage it is expected to push slow adopters to make the move as well. Websites are not the only issue – payment machines like credit card readers can also be insecure and use the older SHA-1 algorithm… and are a lot more expensive and more difficult to get updated. Many of the machines cannot simply upgrade the software – instead new machines must be produced and sent out to retailers.
There are also millions of mobile apps that use encryption. A number are no longer developed but still work and continue to use SHA-1. Others may not get updated often and will not make the switch to SHA-2 for a while. Some companies simply don’t have the funding to update parts of their apps. So there is likely to be a long, uphill battle when it comes to the adoption of a more secure algorithm… the question will be: Will a breach or data loss be less costly than updating the hardware and/or software.