Signal's Post-Quantum PQXDH, Same-Origin Policy, E2EE in the Browser Revisted

Security Cryptography Whatever

We're back! Signal rolled out a protocol change to be post-quantum resilient! Someone was caught intercepting Jabber TLS via certificate transparency! Was the same-origin policy in web browers just a dirty hack all along? Plus secure message format formalisms, and even more beating of the dead horse that is E2EE in the browser.
Transcript: https://securitycryptographywhatever.com/2023/11/07/PQXDH-etc
Links:
- https://zfnd.org/so-you-want-to-build-an-end-to-end-encrypted-web-app/
- https://github.com/superfly/macaroon
- https://cryspen.com/post/pqxdh/
- https://eprint.iacr.org/2023/1390.pdf

"Security Cryptography Whatever" is hosted by Deirdre Connolly (@durumcrustulum), Thomas Ptacek (@tqbf), and David Adrian (@davidcadrian)

Chapter

1. Issues With Encrypted Jabber Communications (00:00:00)

2. App and Web Security Challenges (00:13:53)

3. Benefits and Limitations of Web Encryption (00:22:26)

4. Benefits and Challenges of Browser-Based Cryptography (00:29:54)

5. Web App Security and Distribution Models (00:35:09)

6. Web Security and Signal Key Exchange (00:48:36)

7. X3DH Protocol and Signal's Key Exchange (00:53:49)

8. Camry Encapsulation Attack and Secure Encryption (01:08:11)