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Is the iCloud bit true? I've read HN comments about it, but when I've tried to understand it by searching around it looks like it is encrypted end-to-end and i

Is the iCloud bit true? I've read HN comments about it, but when I've tried to understand it by searching around it looks like it is encrypted end-to-end and in iCloud backup (as long as you're not in China). https://support.apple.com/en-us/HT209110#:~:text=We%20designed%20iMessage%20and%20FaceTime,(s)%20can%20access%20them https://support.apple.com/en-us/HT209110#:~:text=We%20design.... https://support.apple.com/en-us/HT202303 https://support.apple.com/en-us/HT202303 Is there some subtlety I'm missing? That said, on this particular issue I think FB is striking a pretty good middle ground. Keeping things encrypted end-to-end for users, but allowing users to voluntarily report decrypted messages from their end is a good way to combat child abuse imagery and other illegal content without giving FB or governments back door key access. I have a friend on the data science team at whatsapp and his team is responsible for combatting child abuse imagery groups on whatsapp - it's a huge problem. A related comment I wrote when this came up previously: https://news.ycombinator.com/item?id=23553997 https://news.ycombinator.com/item?id=23553997

sneak 6y ago
HT202303 has a list of things that are end-to-end encrypted. iCloud Backup is not in that list. Furthermore, it says: > Messages in iCloud also uses end-to-end encryption. If you have iCloud Backup turned on, your backup includes a copy of the key protecting your Messages. This ensures you can recover your Messages if you lose access to iCloud Keychain and your trusted devices. When you turn off iCloud Backup, a new key is generated on your device to protect future messages and isn't stored by Apple. Note that all of the following are entirely different services: - iMessage (nominally e2e) - Messages in iCloud (e2e, but with the key stored in iCloud Backup if enabled) - this is a way of synchronizing iMessages across all of your devices (independent of backups) - iCloud Backup (not e2e) iCloud Backup is backing up either iMessage plaintext (if Messages in iCloud is off) or iMessage decryption keys (if Messages in iCloud is on), to Apple keys. In private conversations with Apple employees, I understood that this was to be fixed, but then the fix was never released. Then I read this: https://www.reuters.com/article/us-apple-fbi-icloud-exclusive/exclusive-apple-dropped-plan-for-encrypting-backups-after-fbi-complained-sources-idUSKBN1ZK1CT https://www.reuters.com/article/us-apple-fbi-icloud-exclusiv... You can test this state of affairs trivially: 1. Get an iPhone, turn on iCloud Backup and iMessage. 2. Send and receive some iMessages, and do a backup. 3. Throw the iPhone into the river. 4. Call Apple, and claim you forgot your Apple ID password, and need to reset it. They will verify your identity using other information, and reset your Apple ID password. 5. Get a new iPhone. Log in with your reset Apple ID password, and restore from backup. 6. See message plaintext, decrypted with no key from you, your password, or your now-riverbed-domiciled old phone. Apple can decrypt full iCloud Backups without the user's password, or the user's device. These backups contain message history, message attachments, and iMessage decryption keys (which can be used to decrypt iMessage ciphertext which has already transited Apple's iMessage service). Apple is very careful not to ever explicitly lie, but to also say things in such a way that leads people to believe things (that benefit Apple) that aren't strictly true. HT202303 is a very good example of that style. If you don't have a detailed understanding of the different services ("iMessage", "Messages in iCloud", "iCloud Backup", et c) then you will likely misunderstand the statements.
- fossuser 6y ago
  Thanks - I appreciate the clarity of your comment breaking down the details.

sneak 6y ago

HT202303 has a list of things that are end-to-end encrypted. iCloud Backup is not in that list. Furthermore, it says: > Messages in iCloud also uses end-to-end encryption. If you have iCloud Backup turned on, your backup includes a copy of the key protecting your Messages. This ensures you can recover your Messages if you lose access to iCloud Keychain and your trusted devices. When you turn off iCloud Backup, a new key is generated on your device to protect future messages and isn't stored by Apple. Note that all of the following are entirely different services: - iMessage (nominally e2e) - Messages in iCloud (e2e, but with the key stored in iCloud Backup if enabled) - this is a way of synchronizing iMessages across all of your devices (independent of backups) - iCloud Backup (not e2e) iCloud Backup is backing up either iMessage plaintext (if Messages in iCloud is off) or iMessage decryption keys (if Messages in iCloud is on), to Apple keys. In private conversations with Apple employees, I understood that this was to be fixed, but then the fix was never released. Then I read this: https://www.reuters.com/article/us-apple-fbi-icloud-exclusive/exclusive-apple-dropped-plan-for-encrypting-backups-after-fbi-complained-sources-idUSKBN1ZK1CT https://www.reuters.com/article/us-apple-fbi-icloud-exclusiv... You can test this state of affairs trivially: 1. Get an iPhone, turn on iCloud Backup and iMessage. 2. Send and receive some iMessages, and do a backup. 3. Throw the iPhone into the river. 4. Call Apple, and claim you forgot your Apple ID password, and need to reset it. They will verify your identity using other information, and reset your Apple ID password. 5. Get a new iPhone. Log in with your reset Apple ID password, and restore from backup. 6. See message plaintext, decrypted with no key from you, your password, or your now-riverbed-domiciled old phone. Apple can decrypt full iCloud Backups without the user's password, or the user's device. These backups contain message history, message attachments, and iMessage decryption keys (which can be used to decrypt iMessage ciphertext which has already transited Apple's iMessage service). Apple is very careful not to ever explicitly lie, but to also say things in such a way that leads people to believe things (that benefit Apple) that aren't strictly true. HT202303 is a very good example of that style. If you don't have a detailed understanding of the different services ("iMessage", "Messages in iCloud", "iCloud Backup", et c) then you will likely misunderstand the statements.

fossuser 6y ago
Thanks - I appreciate the clarity of your comment breaking down the details.