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Most of iCloud is encrypted at rest. https://support.apple.com/en-us/HT202303 https://support.apple.com/en-us/HT202303

by rscott 9y ago

kingnight 9y ago
Interesting omission of iMessage here... since it's not encrypted at rest on their servers.
- andrewksl 9y ago
  I can't tell if you're implying that they store iMessages unencrypted, but iMessage is encrypted end-to-end. Backups of your phone, which may or may not contain message histories, are only encrypted at rest.
- kingnight 9y ago
  ^ I am implying that they are storing iMessages unencrypted. The iMessages on iPhones/iPads are part of the 'backup' for each device and they are not encrypted at rest on the iCloud server.
  - aeontech 9y ago
    You sound very sure of this, what's your source? As far as I've read, the iCloud backups have always been encrypted at rest, and Apple is apparently working on improving it to the point where they do not hold any decryption keys to the backups [0]. That's why, when you set up a new device, up until now it would not have your message history - because the message history can only be decrypted on devices that are already-authorized. If you restore a backup in its entirety, that includes the message log and the encryption key, but if you set up the device as "new", you only get the newly received messages - since it needs your password to decrypt the backup, it had no way to decrypt the message history from backup on the cloud and only sync that down to the new device (which always bothered me in terms of convenience). I think they're working on improving the usability of it in upcoming releases though. [0] https://9to5mac.com/2016/02/25/apple-working-on-stronger-icloud-backup-encryption-and-iphone-security-to-counter-fbi-unlock-requests/ https://9to5mac.com/2016/02/25/apple-working-on-stronger-icl...
    - kingnight 9y ago
      My source, while I wholly acknowledge this is anecdotal and not evidence, is someone in law enforcement tasked with retrieving message logs for investigations. I was pretty skeptical but I've yet found any proof or documentation from Apple's support docs disproving this. I also recall from the San Bernadino case that the FBI/Apple had the ability to get historic message history from the iCloud backup but the FBI pushed for decrypting the device because of the most recent and not backed up messages. As for your scenario -- doesn't that explicitly confirm that the messages are not encrypted safely at rest? You can restore to an entirely new device, using the same backup, and retrieve the messages.
      - aeontech 9y ago
        > someone in law enforcement tasked with retrieving message logs for investigations. Right, but do they retrieve them from iCloud? Without Apple's assistance, and without knowing the user's password? > I was pretty skeptical but I've yet found any proof or documentation from Apple's support docs disproving this. Well, here's the brief overview: https://support.apple.com/en-us/HT202303 https://support.apple.com/en-us/HT202303 and here's the iOS security whitepaper: https://www.apple.com/business/docs/iOS_Security_Guide.pdf https://www.apple.com/business/docs/iOS_Security_Guide.pdf Which includes a section about iCloud security, including the following section: iCloud secures the content by encrypting it when sent over the Internet, storing it in an encrypted format, and using secure tokens for authentication. I am no security expert, but I am pretty sure FBI wouldn't have a huge fight with Apple if they had any way to get to the data directly (and once they figured out they could use a vuln in the old iOS to break into the device, they did indeed drop the fight). > FBI/Apple had the ability to get historic message history from the iCloud backup Right, because they reset the shooter's Apple ID password. Not because the backup was in plaintext. > As for your scenario -- doesn't that explicitly confirm that the messages are not encrypted safely at rest? You can restore to an entirely new device, using the same backup, and retrieve the messages. How does that follow? You still need to supply your password to decrypt the backup before you can restore it. From the same security whitepaper: When files are created in Data Protection classes that aren’t accessible when the device is locked, their per-file keys are encrypted using the class keys from the iCloud Backup keybag. Files are backed up to iCloud in their original, encrypted state. Files in Data Protection class No Protection are encrypted during transport. The iCloud Backup keybag contains asymmetric (Curve25519) keys for each Data Protection class, which are used to encrypt the per-file keys. For more information about the contents of the backup keybag and the iCloud Backup keybag, see “Keychain Data Protection” in the Encryption and Data Protection section. The backup set is stored in the user’s iCloud account and consists of a copy of the user’s files, and the iCloud Backup keybag. The iCloud Backup keybag is protected by a random key, which is also stored with the backup set. (The user’s iCloud password isn’t utilized for encryption so that changing the iCloud password won’t invalidate existing backups.) While the user’s Keychain database is backed up to iCloud, it remains protected by a UID-tangled key. This allows the Keychain to be restored only to the same device from which it originated, and it means no one else, including Apple, can read the user’s Keychain items. On restore, the backed-up files, iCloud Backup keybag, and the key for the keybag are retrieved from the user’s iCloud account. The iCloud Backup keybag is decrypted using its key, then the per-file keys in the keybag are used to decrypt the files in the backup set, which are written as new files to the file system, thus re-encrypting them as per their Data Protection class.
DavideNL 9y ago
I think that's not true, note this line in the doc you link to: "...and never provides encryption keys to any third parties". The data might be stored encrypted, but Apple seems to have access to the encryption keys. I've read that they need to be able to decrypt data to be able to comply with government requests. I'm not sure if this is still the case now in 2017, but i assume so, until i read otherwise :) https://www.macrumors.com/2016/03/16/apple-to-double-down-icloud-encryption/ https://www.macrumors.com/2016/03/16/apple-to-double-down-ic...
- Spivak 9y ago
  > but Apple seems to have access to the encryption keys Of course, no one claimed that iCould data was E2E. They also need to decrypt the data in order to serve it to their users.
  - DavideNL 9y ago
    > They also need to decrypt the data in order to serve it to their users. That's the point, they don't (and shouldn't) need to. As Apple itself says in the above linked article: "Apple is working to further harden iCloud security so that even it won't be able to access user information stored on its data servers"
    - crooked-v 9y ago
      Web access means that you've always got one of three things: 1) the company has the encryption key 2) you give the company the encryption key each time you log in and they store it temporarily 3) everything is getting decrypted in the browser locally (probably tremendously infeasible)
      - derefr 9y ago
        #3 is how Mega works.

Most of iCloud is encrypted at rest. https://support.apple.com/en-us/HT202303 https://support.apple.com/en-us/HT202303

by rscott 9y ago

Most of iCloud is encrypted at rest. https://support.apple.com/en-us/HT202303 https://support.apple.com/en-us/HT202303

kingnight 9y ago

Interesting omission of iMessage here... since it's not encrypted at rest on their servers.

andrewksl 9y ago
I can't tell if you're implying that they store iMessages unencrypted, but iMessage is encrypted end-to-end. Backups of your phone, which may or may not contain message histories, are only encrypted at rest.
kingnight 9y ago
^ I am implying that they are storing iMessages unencrypted. The iMessages on iPhones/iPads are part of the 'backup' for each device and they are not encrypted at rest on the iCloud server.
- aeontech 9y ago
  You sound very sure of this, what's your source? As far as I've read, the iCloud backups have always been encrypted at rest, and Apple is apparently working on improving it to the point where they do not hold any decryption keys to the backups [0]. That's why, when you set up a new device, up until now it would not have your message history - because the message history can only be decrypted on devices that are already-authorized. If you restore a backup in its entirety, that includes the message log and the encryption key, but if you set up the device as "new", you only get the newly received messages - since it needs your password to decrypt the backup, it had no way to decrypt the message history from backup on the cloud and only sync that down to the new device (which always bothered me in terms of convenience). I think they're working on improving the usability of it in upcoming releases though. [0] https://9to5mac.com/2016/02/25/apple-working-on-stronger-icloud-backup-encryption-and-iphone-security-to-counter-fbi-unlock-requests/ https://9to5mac.com/2016/02/25/apple-working-on-stronger-icl...
  - kingnight 9y ago
    My source, while I wholly acknowledge this is anecdotal and not evidence, is someone in law enforcement tasked with retrieving message logs for investigations. I was pretty skeptical but I've yet found any proof or documentation from Apple's support docs disproving this. I also recall from the San Bernadino case that the FBI/Apple had the ability to get historic message history from the iCloud backup but the FBI pushed for decrypting the device because of the most recent and not backed up messages. As for your scenario -- doesn't that explicitly confirm that the messages are not encrypted safely at rest? You can restore to an entirely new device, using the same backup, and retrieve the messages.
    - aeontech 9y ago
      > someone in law enforcement tasked with retrieving message logs for investigations. Right, but do they retrieve them from iCloud? Without Apple's assistance, and without knowing the user's password? > I was pretty skeptical but I've yet found any proof or documentation from Apple's support docs disproving this. Well, here's the brief overview: https://support.apple.com/en-us/HT202303 https://support.apple.com/en-us/HT202303 and here's the iOS security whitepaper: https://www.apple.com/business/docs/iOS_Security_Guide.pdf https://www.apple.com/business/docs/iOS_Security_Guide.pdf Which includes a section about iCloud security, including the following section: iCloud secures the content by encrypting it when sent over the Internet, storing it in an encrypted format, and using secure tokens for authentication. I am no security expert, but I am pretty sure FBI wouldn't have a huge fight with Apple if they had any way to get to the data directly (and once they figured out they could use a vuln in the old iOS to break into the device, they did indeed drop the fight). > FBI/Apple had the ability to get historic message history from the iCloud backup Right, because they reset the shooter's Apple ID password. Not because the backup was in plaintext. > As for your scenario -- doesn't that explicitly confirm that the messages are not encrypted safely at rest? You can restore to an entirely new device, using the same backup, and retrieve the messages. How does that follow? You still need to supply your password to decrypt the backup before you can restore it. From the same security whitepaper: When files are created in Data Protection classes that aren’t accessible when the device is locked, their per-file keys are encrypted using the class keys from the iCloud Backup keybag. Files are backed up to iCloud in their original, encrypted state. Files in Data Protection class No Protection are encrypted during transport. The iCloud Backup keybag contains asymmetric (Curve25519) keys for each Data Protection class, which are used to encrypt the per-file keys. For more information about the contents of the backup keybag and the iCloud Backup keybag, see “Keychain Data Protection” in the Encryption and Data Protection section. The backup set is stored in the user’s iCloud account and consists of a copy of the user’s files, and the iCloud Backup keybag. The iCloud Backup keybag is protected by a random key, which is also stored with the backup set. (The user’s iCloud password isn’t utilized for encryption so that changing the iCloud password won’t invalidate existing backups.) While the user’s Keychain database is backed up to iCloud, it remains protected by a UID-tangled key. This allows the Keychain to be restored only to the same device from which it originated, and it means no one else, including Apple, can read the user’s Keychain items. On restore, the backed-up files, iCloud Backup keybag, and the key for the keybag are retrieved from the user’s iCloud account. The iCloud Backup keybag is decrypted using its key, then the per-file keys in the keybag are used to decrypt the files in the backup set, which are written as new files to the file system, thus re-encrypting them as per their Data Protection class.

DavideNL 9y ago

I think that's not true, note this line in the doc you link to: "...and never provides encryption keys to any third parties". The data might be stored encrypted, but Apple seems to have access to the encryption keys. I've read that they need to be able to decrypt data to be able to comply with government requests. I'm not sure if this is still the case now in 2017, but i assume so, until i read otherwise :) https://www.macrumors.com/2016/03/16/apple-to-double-down-icloud-encryption/ https://www.macrumors.com/2016/03/16/apple-to-double-down-ic...

Spivak 9y ago
> but Apple seems to have access to the encryption keys Of course, no one claimed that iCould data was E2E. They also need to decrypt the data in order to serve it to their users.
- DavideNL 9y ago
  > They also need to decrypt the data in order to serve it to their users. That's the point, they don't (and shouldn't) need to. As Apple itself says in the above linked article: "Apple is working to further harden iCloud security so that even it won't be able to access user information stored on its data servers"
  - crooked-v 9y ago
    Web access means that you've always got one of three things: 1) the company has the encryption key 2) you give the company the encryption key each time you log in and they store it temporarily 3) everything is getting decrypted in the browser locally (probably tremendously infeasible)
    - derefr 9y ago
      #3 is how Mega works.