Breaking ECDSA

[johndead]

About this crypto issue.

It might be possible to somewhat compute the private key, given several signed datas, their signatures, and the public key.

Thus, since the public keys are known, it might be interesting to have a respository with (different) certificates. The more, the better.

[setarip_old]

Hi!

Forgive my possible ignorance regarding your post but, what, if anything, does this have to do with video (or audio)?

[lightshadow]

About this crypto issue.

It might be possible to somewhat compute the private key, given several signed datas, their signatures, and the public key.

Thus, since the public keys are known, it might be interesting to have a respository with (different) certificates. The more, the better.

No, it doesn't work like that. Todays algorithms are robust to simple Frequency Analysis (http://en.wikipedia.org/wiki/Frequency_analysis).

Please read that link, and follow the links.

Todays algorithms that are classified as cryptographic secure can not be broken, so don't suggest brute force.

[johndead]

This has to do with AACS. You could just make your own certificates.

I'm not suggesting brute force.

I'm suggesting to have a look at the state of the art in cryptanalysis. For example a paper, on citeseer, discussing how the flaws in DSA can be applied to ECDSA, and how they could recover a private key in minutes.

The paper i'm thinking about (http://citeseer.ist.psu.edu/488459.html) is 7 years old. And there probably was some progresse since.

More on citeseer (http://citeseer.ist.psu.edu/).

[lightshadow]

This has to do with AACS. You could just make your own certificates.

I'm not suggesting brute force.

I'm suggesting to have a look at the state of the art in cryptanalysis. For example a paper, on citeseer, discussing how the flaws in DSA can be applied to ECDSA, and how they could recover a private key in minutes.

The paper i'm thinking about (http://citeseer.ist.psu.edu/488459.html) is 7 years old. And there probably was some progresse since.

More on citeseer (http://citeseer.ist.psu.edu/).

Please do just a minimum of research on Wikipedia before asking. It is a very ****** trivial question you are asking.

[johndead]

Hmmm, i'm not really asking a question, i'm not sure what you find trivial either. I'm just suggesting trying to break an ECDSA key.

By the way, i'm not aware of any specific ECDSA attacks article on wikipedia.

[gioowe]

EC-DSA is secure and can not be broken at current time. Even if it is quite useless for AACS. Yes, you could create a fake MKB (when PowerDVD finally verifies signatures ;) ). But fake MBKs (with a higher version) cannot un-revoke keys.

[lightshadow]

Hmmm, i'm not really asking a question, i'm not sure what you find trivial either. I'm just suggesting trying to break an ECDSA key.

By the way, i'm not aware of any specific ECDSA attacks article on wikipedia.

You are asking a question about finding the private key. This is a very ****** trivial question. Please search Wikipedia before posting again.

Edit: and eventhough ecdsa is used in AACS, that doesn't make an AACS that doesn't change anything. ecdsa is also used in openssh. There are general cryptographic forums/newgroups where you can ask these kind of general questions.

I will not comment any further on this.

[gioowe]

By the way it's easier to create a hash collision on SHA-1 then finding 2 private keys (you need AACS CC and AACS LA).