topic Betreff: encryption in Android TV

encryption

okalles — Fri, 03 Nov 2017 11:21:40 GMT

After i got a new motherboard on my KD-55x8505c i cant play from the HDD. If i use cast from my mobile the name of the tv is KD 75 and not KD 55. So the ID is wrong. How can i get back my recordings?

Betreff: encryption

IamNic — Fri, 03 Nov 2017 12:53:02 GMT

Hi okalles,

as far as I am concerned, the recordings are bound to your TV. If you unplug the HDD and plug it into another TV of the same model, you can't play the videos (it is the same for my dads Samsung TV and my Philips TV).

Since your mainboard was exchanged, the HDD does now see your TV as a different one. I am certain it wouldn't change anything if they would have replaced your mainboard with one of a 55" TV.

So I am sorry to tell you that your recordings are unaccessable as far as I can tell.

@Kuschelmonschter might have some more insight on this topic and is pressumably the only person aware of a trick/hack (if there is any) to get back access to your recordings.

- Nic

Betreff: encryption

Kuschelmonschter — Fri, 03 Nov 2017 13:43:03 GMT

Fully agree. There is no trick or hack that I am aware of to circumvent the encryption.

Betreff: encryption

okalles — Fri, 03 Nov 2017 15:31:25 GMT

I thought that if Sony can encrypt they also can decrypt. The case is an warranty claim. Bought tv 15 months ago.

Betreff: encryption

Jecht_Sin — Sat, 04 Nov 2017 06:30:29 GMT

okalles wrote:
I thought that if Sony can encrypt they also can decrypt. The case is an warranty claim. Bought tv 15 months ago.

No, it doesn't work like that. It isn't Sony decrypting, it's the algorithm. And the algorithm to be 100% (well.. ideally) safe needs to be able to decrypt only on the platform that made the encryption. It's the encrypting side owning the (highly hidden) encryption key, and once you replace the motherboard (or even just after resetting to factory settings) that key has gone, getting replaced with a newly generated (I think randomly) one.

It's the price of security, allowing a backdoor would render the encryption much less secure (since the key wouldn't be private but somehow public instead).

Betreff: encryption

Kuschelmonschter — Sat, 04 Nov 2017 06:33:29 GMT

You still have access to recordings after factory resetting. Suppose the key is somewhere in the hardware..

Betreff: encryption

Jecht_Sin — Sat, 04 Nov 2017 06:59:16 GMT

@Kuschelmonschter wrote:
You still have access to recordings after factory resetting. Suppose the key is somewhere in the hardware..

Well, I tested it with the (broken) internal memory extension. After a reset it didn't recognize it. But thinking better about it it can be because after a reset it wouldn't be clean to use old data. I thought the key was tied to the Android ID, that at least on mobile gets re-created after each reset (so it says Titanium Backup on rooted phones). But sure, it must be in tied to the HW, then.

Then I think, for example, that the external disks (which is a recent feature) used as extended mass memory in the PS4, have the key tied to the PSN ID. So yeah, there are various options. As long as the key is not easily accessible by the public.

Betreff: encryption

okalles — Sat, 04 Nov 2017 08:07:19 GMT

So u mean that the Sonys service partner the company who put the new motherboard in my tv can do thet? And, do u think that the wrong name on the tv can be exchanges back to KD-55x from the wrong name KD-75x.Could This may be the reason for the problem.

Betreff: encryption

Jecht_Sin — Sat, 04 Nov 2017 08:18:06 GMT

@okalles wrote:
So u mean that the Sonys service partner the company who put the new motherboard in my tv can do thet? And, do u think that the wrong name on the tv can be exchanges back to KD-55x from the wrong name KD-75x.Could This may be the reason for the problem.

No, the HW now is different, no one can do it. Encryption is for security (and in this case DRM/copyright protection), if the algorithm gets the encryption key from the motherboard the content of that hard disk is completely useless now. Unless of cracking the encryption key from a PC, but good luck with that...

Still yes, something is wrong with that KD-75. What does it says in the help (pushing the button in the lower left corner in the remote)? The model is written in the top-right corner. It won't help you with the encrypted data, but it shouldn't report a wrong model either. But yet again, they are two distinct issues.

Betreff: encryption

okalles — Sat, 04 Nov 2017 10:13:00 GMT

Hmm- Dont know what 2 do. Thought if i brought tv and hdd to service the workshop they could pair it together again.

Betreff: encryption

IamNic — Sat, 04 Nov 2017 16:25:55 GMT

Hi okalles,

the videos are definetly bound to your original mobo (motherboard).

It doesn't matter, that they put in a mainboard of a 75 inch TV, since even with the mobo of another 55 inch TV the videos would not be playable.

I assume the repair-shop only has mobos of 75 inch TV in stock, since they can be used to replace the mobos on all the smaller versions as well.

It should be possible to rename your TV from the default name to anther one though (like "okalles-TV" or something else) if you change its "network name" (the name it will be shown inside your home network).

That is probably possible in the WiFi settings (I don't own the TV you have, so I can't guide you to the setting unfortunately).

The recordings are definetly lost

- Nic