If a proposal currently before the European Parliament and Council passes, the security of HTTPS in your browser may get a lot worse. A proposed amendment to Article 45 in the EU’s Digital Identity Framework (eIDAS) would have major, adverse security effects on millions of users browsing the web.
The amendment would require browsers to trust third parties designated by the government, without necessary security assurances. But trusting a third party that turns out to be insecure or careless could mean compromising user privacy, leaking personal or financial information, being targeted by malware, or having one’s web traffic snooped on.
What is a CA?
Certificate Authorities (CAs) are trusted notaries which underpin the main transport security model of the Web and other internet services. When you visit an HTTPS site, your browser needs to know that you are communicating with the site you requested, and that trust is ultimately anchored by the CA. CAs issue digital certificates that certify the ownership and authenticity of a public encryption key. The CA verifies that this key does belong to that website. For a certificate to be valid in a browser, it must be signed by a CA. The fundamental duty of the CA is to verify certificate requests submitted to it, and sign only those that it can verify as legitimate.
What is a Root Store?
Operating systems and browsers choose which CAs meet their standards and provide benefits to their users. They store those CAs’ root certificates in their root store. A CA that does not meet these rigid requirements are not allowed in these root stores.
The Dangers of Requiring Government Mandated CAs
The proposed amendment requires CAs in all major root stores that are nationally approved by EU member countries. The amendment has no assurance that these CAs must meet the root store’s security requirements, no listed mechanisms to challenge their inclusion, and no required transparency.
Even though eIDAS wasn't intended to be anti-democratic, it could open the path to more authoritarian surveillance.
This can lead to issues beyond poorly managed practices from a faulty or careless CA. If browsers can’t revoke a CA that has been flagged by their standards, their response to a security incident will be delayed.
This setup could also tempt governments to try “Machine-in-the-Middle”(MITM) attacks on people. In August 2019, the government of Kazakhstan tried to require installation of a certificate to scan citizen traffic for “security threats.” Google Chrome, Mozilla Firefox, and Apple Safari blocked this certificate. They were able to take this stand because they run independent root stores with proper security controls. Under this new regulation, this would not be as easy to do. The EU has much more reach and impact than one country. Even though eIDAS wasn't intended to be anti-democratic, it could open the path to more authoritarian surveillance.
If adopted, the amendment would roll back security gains that so many worked hard to achieve in the past decade. The amendment should be dropped. Instead, these CAs should be pushed to meet requirements for transparency, security, and incident response.