Factorization weakness lets attackers impersonate key holders and decrypt their data. A flaw in a widely used code library has fatally undermined the security of millions of encryption keys used in some of the highest-stakes settings, including:
- national identity cards
- software- and application-signing
- trusted platform modules protecting government and corporate computers.
The weakness allows attackers to calculate the private portion of any vulnerable key using nothing more than the corresponding public portion. Hackers can then use the private key to impersonate key owners, decrypt sensitive data, sneak malicious code into digitally signed software, and bypass protections that prevent accessing or tampering with stolen PCs. The five-year-old flaw is also troubling because it's located in code that complies with two internationally recognized security certification standards that are binding on many governments, contractors, and companies around the world. The code library was developed by German chipmaker Infineon and has been generating weak keys since 2012 at the latest.
The flaw resides in the Infineon-developed RSA Library version v1.02.013, specifically within an algorithm it implements for RSA primes generation. The library allows people to generate keys with smartcards rather than with general-purpose computers, which are easier to infect with malware and hence aren't suitable for high-security uses.