By Fahmida Y. Rashid
Jan. 3, 2017
From May to October 2016, the use of SHA-1 on the web fell from 3.5 percent to less than 1 percent, as measured by Firefox Telemetry. Enterprises can’t be complacent, though, since recent estimates from Venafi suggest approximately 60 million websites still rely on the insecure encryption algorithm.
“We look forward to the industry's movement toward greater use of stronger certificates like SHA-256,” Wojtyniak said.
Crypto is still king
Cryptography has taken quite a beating over the past few months, with researchers developing cryptographic attacks such as Drown, which can be used to decrypt TLS connections between a user and a server if the server supports SSLv2, and Sweet32, a way to attack encrypted web connections by generating huge amounts of web traffic.
Nation-state actors also have encryption in their crosshairs. Late last year, Juniper Networks uncovered spying code implanted in specific models of its firewall and Virtual Private Network appliances. Many experts believe the NSA was involved.
Shortly after the cache of hacking tools allegedly belonging to the NSA made its way to underground markets this summer, Cisco discovered a vulnerability in its IOS, IOS XE, and IOS XR software that powers many of its networking devices. The flaw, which could be used to extract sensitive information from device memory, was similar to the vulnerability exploited by the tools and was related to how the operating system processed the key exchange protocol for VPNs, Cisco said.
Even Apple’s iMessage app, the poster child for how companies can bring end-to-end encryption to the masses, had its share of issues. Cryptography professor Matthew Green and his team of students at Johns Hopkins University were able to develop a practical adaptive chosen ciphertext attack that could decrypt iMessage payloads and attachments under specific circumstances. The team also found that iMessage lacked the forward secrecy mechanism, meaning attackers could decrypt previously encrypted messages, such as those stored in iCloud. Forward secrecy works by generating a new key after a set period of time so that even if the attackers obtained the original key, the previously encrypted messages can’t be cracked.
One thing remains clear despite all the bad news: Cryptography is not broken. The mathematics behind cryptographic calculations remain strong, and encryption is still the best way to protect information.
“The latest attacks have not been on the math, but on the implementation,” Waters says.
In fact, encryption works so well that attackers rely on it, too. Criminals are equally as capable of obtaining keys and certificates to hide their activities inside encrypted traffic. The fact that this attack vector is fast becoming default behavior for cybercriminals “almost counteracts the whole purpose of adding more encryption,” Bocek says.