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Playstation 5 root keys obtained

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Re: Playstation 5 root keys obtained

#81

Post by magospietato »

wizardofdos wrote: post #73
politelemon wrote: post #41

Earlier quoted context omitted.

These keys are symmetric, so they can be used for decryption. With these symmetric keys you might be able to decrypt games, videos, save files etc sitting on the disk. I don't believe signing will be possible, nobody uses symmetric keys for signing games. What this does is increase the possibility of someone finding how to bypass the signature verification check and then running their own code.

Why don't they use asymmetric keys for everything?

The most common asymmetric encryption algorithm (RSA) can only encrypt a plaintext of limited size. Depending on padding scheme, a 2048 bit RSA key can encrypt a message of up to ~245 bytes.

Typically to securely encrypt a message you use symmetric key encryption. Then to allow a third party to decrypt that message, you encrypt the symmetric key using the third party's asymmetric key.

Re: Playstation 5 root keys obtained

#82

Post by oleganza »

Nursie wrote: post #77
wizardofdos wrote: post #73

Earlier quoted context omitted.

Why don't they use asymmetric keys for everything?

Because we don't generally use asymmetric keys for much data encryption. The operations are (IIRC) comparatively computationally expensive.

First of all, we are talking about on-device decryption, so there is no difference in terms of security whether people extract a symmetric secret key or an asymmetric secret key.

Secondly, yes, asymmetric encryption is slower, so you almost always use hybrid scheme: asymmetric scheme (ElGamal, for instance) for encrypting the symmetric key, and then a symmetric scheme (e.g. AES) for the bulk of the data.

Only in very exotic protocols such as digicash blind signatures or anonymous credentials with "algebraic MACs", you want your actual content encrypted directly via ElGamal or RSA, so that you can do some operations or proofs about the ciphertext — in those cases you can't encrypt symmetrically as that would erase all the algebraic relations.

Re: Playstation 5 root keys obtained

#83

Post by scott_w »

vmception wrote: post #51
Aissen wrote: post #36

Earlier quoted context omitted.

If you look at sales chart, Sony is selling as many PS5 as they sold PS4 during the same launch period. It's just that demand is higher; the fact that they are able to make as much during a chip shortage says a lot of their supply chain expertise (same could be said of MS, Nintendo, Samsung, LG, Apple etc.).

Expertise being a euphemism for relationships to skip the queue.

Relationships, knowledge and ability to long-term bulk-buy in order to skip the queue. Suppliers want to work with customers who they know will be large customers in 5 years time and not just some random bloke who rocks up and tries to buy 30 chips on a Tuesday.

Re: Playstation 5 root keys obtained

#84

Post by carpenecopinum »

Nursie wrote: post #77
wizardofdos wrote: post #73

Earlier quoted context omitted.

Why don't they use asymmetric keys for everything?

Because we don't generally use asymmetric keys for much data encryption. The operations are (IIRC) comparatively computationally expensive.

For that reason, the usual trick is to use asymmetric encryption to protect a symmetric key (a fresh one per payload) that is then used for the actual payload. That way you get the speed of symmetric encryption with the benefits of asymmetric ones. (Though evidently that's not what the PS5 uses here, otherwise it would be useless to read out one symmetric key).

Re: Playstation 5 root keys obtained

#85

Post by rich_sasha »

Given all the issues described in this thread, what is the upside of a game console (non-gamer)? Why not get a PC that you can automatically use for other things, can play games from any vendor etc (some of the issues mentioned in the thread).

Are consoles cheaper “per transistor” or sth? If so, why? Is it about the vendor locking you in and charging more per game? That would seem even more skewed against the buyer: buy this pseudo-pc so we can sell you expensive, limited-choice software.

Re: Playstation 5 root keys obtained

#86

Post by factorialboy »

rich_sasha wrote: post #85

Given all the issues described in this thread, what is the upside of a game console (non-gamer)? Why not get a PC that you can automatically use for other things, can play games from any vendor etc (some of the issues mentioned in the thread). Are consoles cheaper “per transistor” or sth? If so, why? Is it about the vendor locking you in and charging more per game? That would seem even more skewed against the buyer:…

I agree with a sentiment.

The only pro I can see at the moment for any console is the ability to place it in the living room for the family to share a casual gaming / entertainment experience.

I do have a PC and, while not a "gamer", I enjoy hitting back on the old classics (Age of Empires 2 DE) from time to time.

But that is a personal gaming experience, not to be shared with others in my home.

Re: Playstation 5 root keys obtained

#87

Post by oxplot »

carpenecopinum wrote: post #84
Nursie wrote: post #77

Earlier quoted context omitted.

Because we don't generally use asymmetric keys for much data encryption. The operations are (IIRC) comparatively computationally expensive.

For that reason, the usual trick is to use asymmetric encryption to protect a symmetric key (a fresh one per payload) that is then used for the actual payload. That way you get the speed of symmetric encryption with the benefits of asymmetric ones. (Though evidently that's not what the PS5 uses here, otherwise it would be useless to read out one symmetric key).

And to add to that: you should use as many different symmetric keys as possible as long as asymmetric decryption of the key doesn't overly degrade performance.

Re: Playstation 5 root keys obtained

#89

Post by shocks »

rich_sasha wrote: post #85

Given all the issues described in this thread, what is the upside of a game console (non-gamer)? Why not get a PC that you can automatically use for other things, can play games from any vendor etc (some of the issues mentioned in the thread). Are consoles cheaper “per transistor” or sth? If so, why? Is it about the vendor locking you in and charging more per game? That would seem even more skewed against the buyer:…

I already spend all day sat at my desk.

I was a “PC gamer” for years, but consoles are better for plug and play group/sofa gaming.

Re: Playstation 5 root keys obtained

#90

Post by dajonker »

rich_sasha wrote: post #85

Given all the issues described in this thread, what is the upside of a game console (non-gamer)? Why not get a PC that you can automatically use for other things, can play games from any vendor etc (some of the issues mentioned in the thread). Are consoles cheaper “per transistor” or sth? If so, why? Is it about the vendor locking you in and charging more per game? That would seem even more skewed against the buyer:…

Convenience and cost for me. You get significantly better hardware for your money than a PC for the same price, while it is guaranteed that all games you can buy will run as the developer intended it. Just turn it on and play.
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