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JonDo possibly broken/compromised?

Posted: Wed Nov 19, 2014 10:18
by User654
I used this service a bit and so far I like it. But there was a thing that I thought that could compromise the entire JonDo service.

From what I learned, this service uses RSA-1024 and AES-128, in a similar fashion like TLS. While AES-128 is sufficient for now, I believe that RSA-1024 could be cracked by a global adversary, given the scandals that happened 1 year ago. "Officially", the highest RSA-number that is broken is RSA-768 (that was 4-5 years ago), but given the fact that a government agency may not disclose higher cracked numbers, we never know.

Further looking into the certificates, the mix and operator certificates are using DSA-1024, while the "top operator/root certificate" on that chain (usually jondos operator) has a DSA-2048 certificate and is said to be a "top CA". What does that mean? DSA is supposedly somewhat different, yet in terms of security roughly identical to RSA.

I am aware that doubling the key size is a lot more computing work for the mix servers. I also heard that an improved hash algorithm has been in use in a beta version, but I am not sure if the beta is safe to use for an casual user. The current hash algorithm is SHA-1 for the mix servers and SHA-1 is somewhat old. If I got any mistakes, I am a complete noob in cryptography.

I do not want to discredit this service, but is this service currently safe? If the encryption could be cracked, the user could be deanonymized, right? (especially if the connection between the client and the first mix cascade is targeted?!)

Re: JonDo possibly broken/compromised?

Posted: Wed Nov 19, 2014 14:02
by sovereignpress
User654 wrote:I used this service a bit and so far I like it. But there was a thing that I thought that could compromise the entire JonDo service.
Okay.
From what I learned, this service uses RSA-1024 and AES-128, in a similar fashion like TLS. While AES-128 is sufficient for now, I believe that RSA-1024 could be cracked by a global adversary, given the scandals that happened 1 year ago. "Officially", the highest RSA-number that is broken is RSA-768 (that was 4-5 years ago), but given the fact that a government agency may not disclose higher cracked numbers, we never know.
RSA is used for encryption and digital signatures. DSA is only used for digital signatures (signing). Network traffic is encrypted with AES-128, which is secure. The actual digital signing uses DSA-128, which is also secure. DSA-128 and RSA-128 are not the same.

I should also add that it appears that JonDo mix servers no longer use RSA.
Further looking into the certificates, the mix and operator certificates are using DSA-1024, while the "top operator/root certificate" on that chain (usually jondos operator) has a DSA-2048 certificate and is said to be a "top CA". What does that mean? DSA is supposedly somewhat different, yet in terms of security roughly identical to RSA.
They are not roughly identical. RSA is based on factoring, and it is easier to crack than DSA. DSA-128 is secure.
I do not want to discredit this service, but is this service currently safe? If the encryption could be cracked, the user could be deanonymized, right? (especially if the connection between the client and the first mix cascade is targeted?!)
The network is secure.

As an added bonus, if I recall correctly, Tor uses similar encryption.

Re: JonDo possibly broken/compromised?

Posted: Sun Dec 07, 2014 14:30
by Maser
Anyone can explain this content shown in the picture?
[img=http://abload.de/thumb/untitledyfia9.jpg]
This picture shows the certificates, this is the only way how I can see the key strength of said certificates (in this example DSA encryption with a key length of 1024). Further information please? Does this only shows the encryption method of the CAs?

Most certificates seem to use DSA 1024, while root certificates mostly use DSA 2048.