3 ms·

That is not true. iMessage content is encrypted in iCloud with keys stored in your keychain only accessible to your devices. When you add a new device to your a

by mike_d 3y ago

That is not true. iMessage content is encrypted in iCloud with keys stored in your keychain only accessible to your devices. When you add a new device to your account it learns the keys from one of your existing devices and requires touch/face ID approval. In an "all devices lost" situation the keychain is backed up to iCloud but encrypted using a key stored in an HSM that requires authentication using things only you know but are never transmitted to Apple using https://en.wikipedia.org/wiki/Secure_Remote_Password_protocol https://en.wikipedia.org/wiki/Secure_Remote_Password_protoco...

modeless 3y ago
You have been misled. The truth is that the iMessage keys stored in iCloud are accessible to Apple unless you have enabled the non-default Advanced Data Protection (ADP) feature. This is clearly documented by Apple themselves[1]. And even if you do enable it, your messages are still accessible to Apple in the iCloud backups of the people you are messaging, since they likely didn't enable a non-default feature like ADP. Defaults matter! [1] https://support.apple.com/en-us/102651 https://support.apple.com/en-us/102651
- mike_d 3y ago
  From that page: "For additional privacy and security, 14 data categories — including Health and passwords in iCloud Keychain — are end-to-end encrypted. Apple doesn't have the encryption keys for these categories, and we can't help you recover this data if you lose access to your account." The page goes on to list iMessage as always E2E. Other types of data like Calendar are only encrypted in transit and at rest so they can do server side processing. You may also find their legal explanation a bit clearer: https://www.apple.com/legal/privacy/data/en/messages/ https://www.apple.com/legal/privacy/data/en/messages/ Specifically: "We designed iMessage to use end-to-end encryption, so there’s no way for Apple to decrypt the content of your conversations when they are in transit between devices. Attachments you send over iMessage (such as photos or videos) are encrypted so that no one but the sender and receiver(s) can access them."
  - modeless 3y ago
    > The page goes on to list iMessage as always E2E It does no such thing. I'm sorry, Apple's wording is precise but quite confusing. The link again is: https://support.apple.com/en-us/102651 https://support.apple.com/en-us/102651 You are likely being misled by Apple's confusing naming. In the "Data categories and encryption" table, "Messages in iCloud" is listed as always end-to-end encrypted, with a footnote. However this is not telling you that all iMessage messages are always stored end-to-end encrypted. In fact "Messages in iCloud" refers to an optional feature of iMessage. The table is telling you that if you enable the "Messages in iCloud" feature, your messages are end-to-end encrypted. But wait, remember that footnote! Follow the footnote reference to find out that in fact, as I said, the end-to-end encryption is broken by iCloud backup unless the optional ADP is enabled. This line of the table is extremely misleading to say the least. But what if you don't enable the "Messages in iCloud" feature? Then your iCloud backup simply includes your messages, which again are not end-to-end encrypted unless you enable the optional ADP. That's covered under the "iCloud Backup (including device and Messages backup)" line in the "Data categories and encryption" table. Note that in this table "In transit & on server" means "not end-to-end". The other page you link states that messages are "encrypted" in iCloud backups; it does not state that they are end-to-end encrypted in iCloud backups, in contrast to the following sentence which specifically calls out end-to-end encryption. The page seems designed to mislead, but it is technically not incorrect because it does not specifically claim end-to-end encryption of iCloud backups. The iCloud documentation I linked, on the other hand, is confusing but definitive and unambiguous if carefully read.
    - mike_d 3y ago
      Ah, I see where you are getting confused. Yes the Messages in iCloud encryption keys are escrowed with Apple in some cases. The keys are stored inside an HSM that requires a secret known by the user and not Apple. The underlying process is documented in this webpage and the linked PDF https://support.apple.com/guide/security/escrow-security-for-icloud-keychain-sec3e341e75d/web https://support.apple.com/guide/security/escrow-security-for...
      - modeless 3y ago

by mike_d 3y ago

modeless 3y ago

You have been misled. The truth is that the iMessage keys stored in iCloud are accessible to Apple unless you have enabled the non-default Advanced Data Protection (ADP) feature. This is clearly documented by Apple themselves[1]. And even if you do enable it, your messages are still accessible to Apple in the iCloud backups of the people you are messaging, since they likely didn't enable a non-default feature like ADP. Defaults matter! [1] https://support.apple.com/en-us/102651 https://support.apple.com/en-us/102651

mike_d 3y ago
From that page: "For additional privacy and security, 14 data categories — including Health and passwords in iCloud Keychain — are end-to-end encrypted. Apple doesn't have the encryption keys for these categories, and we can't help you recover this data if you lose access to your account." The page goes on to list iMessage as always E2E. Other types of data like Calendar are only encrypted in transit and at rest so they can do server side processing. You may also find their legal explanation a bit clearer: https://www.apple.com/legal/privacy/data/en/messages/ https://www.apple.com/legal/privacy/data/en/messages/ Specifically: "We designed iMessage to use end-to-end encryption, so there’s no way for Apple to decrypt the content of your conversations when they are in transit between devices. Attachments you send over iMessage (such as photos or videos) are encrypted so that no one but the sender and receiver(s) can access them."
- modeless 3y ago
  > The page goes on to list iMessage as always E2E It does no such thing. I'm sorry, Apple's wording is precise but quite confusing. The link again is: https://support.apple.com/en-us/102651 https://support.apple.com/en-us/102651 You are likely being misled by Apple's confusing naming. In the "Data categories and encryption" table, "Messages in iCloud" is listed as always end-to-end encrypted, with a footnote. However this is not telling you that all iMessage messages are always stored end-to-end encrypted. In fact "Messages in iCloud" refers to an optional feature of iMessage. The table is telling you that if you enable the "Messages in iCloud" feature, your messages are end-to-end encrypted. But wait, remember that footnote! Follow the footnote reference to find out that in fact, as I said, the end-to-end encryption is broken by iCloud backup unless the optional ADP is enabled. This line of the table is extremely misleading to say the least. But what if you don't enable the "Messages in iCloud" feature? Then your iCloud backup simply includes your messages, which again are not end-to-end encrypted unless you enable the optional ADP. That's covered under the "iCloud Backup (including device and Messages backup)" line in the "Data categories and encryption" table. Note that in this table "In transit & on server" means "not end-to-end". The other page you link states that messages are "encrypted" in iCloud backups; it does not state that they are end-to-end encrypted in iCloud backups, in contrast to the following sentence which specifically calls out end-to-end encryption. The page seems designed to mislead, but it is technically not incorrect because it does not specifically claim end-to-end encryption of iCloud backups. The iCloud documentation I linked, on the other hand, is confusing but definitive and unambiguous if carefully read.
  - mike_d 3y ago
    Ah, I see where you are getting confused. Yes the Messages in iCloud encryption keys are escrowed with Apple in some cases. The keys are stored inside an HSM that requires a secret known by the user and not Apple. The underlying process is documented in this webpage and the linked PDF https://support.apple.com/guide/security/escrow-security-for-icloud-keychain-sec3e341e75d/web https://support.apple.com/guide/security/escrow-security-for...
    - modeless 3y ago