Matthew GreenFeb 12, 2025
I wrote a bit more about the UK’s recent move to allegedly demand backdoors in Apple encryption. https://blog.cryptographyengineering.com/2025/02/12/u-k-asks-to-backdoor-icloud-backup-encryption/
U.K. asks to backdoor iCloud Backup encryption

I’m supposed to be finishing a wonky series on proof systems (here and here) and I promise I will do that this week. In the midst of this I’ve been a bit distracted by world events. Las…

A Few Thoughts on Cryptographic Engineering
Show threadaspragg

@matthew_d_green

> your backups would be encrypted securely under your phone’s passcode — something you should remember because you have to type it in every day

Securely? But aren't phone passcodes only 4-6 digits long? And if someone has access to the encrypted data, won't they have unlimited attempts to decrypt it? Wouldn't that make a brute-force attack trivial?

Feb 12, 2025 at 10:55pmWeb
Show threadidkrnFeb 13, 2025
@aspragg for unlocking, you need the key that is also stored in the hardware. You may need that as well for the backups
Show threadB-rad 🏳️‍🌈👨‍💻Feb 13, 2025
@aspragg @matthew_d_green the passcode is entangled with and protecting the actual encryption keys. It’s described in detail in the platform security guide https://support.apple.com/guide/security/encryption-and-data-protection-overview-sece3bee0835/web
Encryption and Data Protection overview

Apple devices have encryption features to safeguard user data and to help ensure that only trusted code apps run on a device.

Apple Support