Dual_EC_DRBG random number generator

From 2004 to 2013, the default cryptographically secure pseudorandom number generator (CSPRNG) in BSAFE was Dual_EC_DRBG, which contained an alleged backdoor from NSA, in addition to being a biased and slow CSPRNG.^[4] The cryptographic community had been aware that Dual_EC_DRBG was a very poor CSPRNG since shortly after the specification was posted in 2005, and by 2007 it had become apparent that the CSPRNG seemed to be designed to contain a hidden backdoor for NSA, usable only by NSA via a secret key.^[5] In 2007, Bruce Schneier described the backdoor as "too obvious to trick anyone to use it."^[5] The backdoor was confirmed in the Snowden leaks in 2013, and it was insinuated that NSA had paid RSA Security US$10 million to use Dual_EC_DRBG by default in 2004,^[3] though RSA Security denied that they knew about the backdoor in 2004. The Reuters article which revealed the secret $10 million contract to use Dual_EC_DRBG described the deal as "handled by business leaders rather than pure technologists".^[3] RSA Security has largely declined to explain their choice to continue using Dual_EC_DRBG even after the defects and potential backdoor were discovered in 2006 and 2007, and has denied knowingly inserting the backdoor.^[6]

So why would RSA pick Dual_EC as the default? You got me. Not only is Dual_EC hilariously slow – which has real performance implications – it was shown to be a just plain bad random number generator all the way back in 2006. By 2007, when Shumow and Ferguson raised the possibility of a backdoor in the specification, no sensible cryptographer would go near the thing. And the killer is that RSA employs a number of highly distinguished cryptographers! It's unlikely that they'd all miss the news about Dual_EC.

As a cryptographically secure random number generator is often the basis of cryptography, much data encrypted with BSAFE was not secure against NSA. Specifically it has been shown that the backdoor makes SSL/TLS completely breakable by the party having the private key to the backdoor (i.e. NSA).^[5] Since the US government and US companies have also used the vulnerable BSAFE, NSA can potentially have made US data less safe, if NSA's secret key to the backdoor had been stolen. It is also possible to derive the secret key by solving a single instance of the algorithm's elliptic curve problem^[5] (breaking an instance of elliptic curve cryptography is considered unlikely with current computers and algorithms, but a breakthrough may occur).

In June 2013, Edward Snowden began leaking NSA documents. In November 2013, RSA switched the default to HMAC DRBG with SHA-256 as the default option. The following month, Reuters published the report based on the Snowden leaks stating that RSA had received a payment of $10 million to set Dual_EC_DRBG as the default.^[3]

With subsequent releases of Crypto-C Micro Edition 4.1.2 (April 2016), Micro Edition Suite 4.1.5 (April 2016) and Crypto-J 6.2 (March 2015), Dual_EC_DRBG was removed entirely.

Extended Random TLS extension

"Extended Random" was a proposed extension for the Transport Layer Security (TLS) protocol, submitted for standardization to IETF by an NSA employee,^[7] although it never became a standard. The extension would otherwise be harmless, but together with the Dual_EC_DRBG, it would make it easier to take advantage of the backdoor.^[8][9]

The extension was previously not known to be enabled in any implementations, but in December 2017, it was found enabled on some Canon printer models, which use the RSA BSAFE library, because the extension number conflicted a part of TLS version 1.3.^[9]