Post-Quantum iMessage with Douglas Stebila

Security Cryptography Whatever

Apple iMessage is getting a big upgrade! Not only are they rolling out ratcheting, but they’re going post-quantum, AND they’re doing post-quantum ratcheting! Douglas Stebila joined us to talk about his security analysis of the new PQ3 protocol update and not indulge our wild Apple speculations:
Transcript: https://securitycryptographywhatever.com/2024/03/03/post-quantum-imessage-with-douglas-stebila/
Links:
- https://security.apple.com/blog/imessage-pq3/
- Security analysis of the iMessage PQ3 protocol
https://security.apple.com/assets/files/A_Formal_Analysis_of_the_iMessage_PQ3_Messaging_Protocol_Basin_et_al.pdf
- Ratcheting design: https://eprint.iacr.org/2024/220.pdf
- When Messages are Keys: Is HMAC a dual-PRF?: https://eprint.iacr.org/2023/861.pdf
- Real World Deniability in Messaging: https://eprint.iacr.org/2023/403.pdf
- Padmé: https://www.petsymposium.org/2019/files/papers/issue4/popets-2019-0056.pdf
- Max Headroom: https://www.youtube.com/watch?v=cYdpOjletnc
- Extended Canetti-Krawczyk model: https://iacr.org/archive/eurocrypt2001/20450451.pdf
- Douglas Stebila: https://www.douglas.stebila.ca/
"Security Cryptography Whatever" is hosted by Deirdre Connolly (@durumcrustulum), Thomas Ptacek (@tqbf), and David Adrian (@davidcadrian)

Chapter

1. Post-Quantum iMessage with Douglas Stebila (00:00:00)

2. Apple's Post-Quantum iMessage Security Analysis (00:00:12)

3. Hybrid Key Agreement Protocols and Security (00:17:08)

4. Cryptographic Deniability in Messaging (00:27:47)

5. Messaging Security Protocol Updates (00:39:36)