0
votes
1answer
22 views

How is the Premaster secret used in TLS generated?

I believe that it uses some combination of the random values sent in the hello messages. From RFC 2246: (TLSv1.0) RSA encrypted premaster secret message Meaning of this message: If RSA is ...
5
votes
2answers
118 views

Security sanity check

A company whose services I'm trying to integrate uses this protocol: An AES key is embedded in an Android library. To authenticate itself, the library sends a SHA1 hash of the key over plain HTTP. ...
1
vote
1answer
135 views

When SSL detect a replay attack?

Suppose an attacker records all messages of a SSL handshake (RSA one-way), and starts a replay attack. When (after which message) can the server possibly detect the attack? Now suppose the attacker ...
9
votes
2answers
1k views

Can I determine a private key given the encrypted data and corresponding cleartext?

If I know that Data A is an encrypted form of Data B is that sufficient information to determine the private key?
0
votes
3answers
142 views

Is all RSA encryption now considered insecure? (Notably SSH and SSL)

Some of the leaks which emerged during/after Snowden concerned the fact that the NSA was paying the organization behind RSA a lot of money in order for them to systematically weaken the encryption by ...
0
votes
3answers
443 views

Any alternative available for RSA? Is the web still visible to NSA?

After the Snowden revelations, is there any mass change being carried out to HTTPS protocol? As far as I understood, any HTTPS communication is still visible to NSA as they can compromise the RSA ...
0
votes
1answer
108 views

Possible to Derive Private Key from Public Key Given Enough Computing Power? [closed]

Is it possible via brute force to derive a private key from a public key (such as a website's SSL certificate)? If so, how much computing power would you need to make it feasible, compared to say, ...
1
vote
0answers
96 views

Is my approach to anonymous certificate based HTTP(s) authentication and secure private messaging sound?

I'm trying to work out a somewhat anonymous secure messaging system, and was hoping someone could validate my overall approach. Keep in mind, this all takes place over HTTPS. Authentication While ...
2
votes
2answers
300 views

Why should the dh keylength match rsa length in tls?

A few sources state that the DH keylength (bits of the prime) should match the keylength of rsa for TLS. For example SSL_set_tmp_dh(3) from openssl has example code on how to match the dh parameters ...
2
votes
2answers
186 views

For DHE_RSA_.. Cipher Suites what is RSA used for?

In addition to achieving PFS with DHE, we want as little as possible to be revealed when the server's private key is revealed. So, what is RSA used for in DHE_RSA cipher suites? What does the server ...
3
votes
1answer
228 views

Is TLS 1.0 sufficiently secure for a bank?

I disabled SSL2 and SSL3 in my Firefox browser, version 24. I only enabled TLS 1.1 and 1.2. Unfortunately when I went to my bank's website, I found that it didn't work until I re-enabled TLS 1.0. ...
6
votes
2answers
1k views

1024-bit DHE vs 2048-bit RSA

Currently with apache/mod_ssl, if DHE is enabled then a 1024-bit ephemeral key will be used. I found the following quote in Adam Langley's blog: Ideally the DH group would match or exceed the RSA ...
1
vote
1answer
211 views

Reason for using Asymmetric encryption along with SHA256

I got a document with integration with another application. They mentioned I need to hash and then encrypt data with my private key before sending it over HTTPS. By doing this, they are making sure ...
2
votes
1answer
394 views

Does the NSA X-Keyscore apply for HTTPS traffic? [closed]

See X-Keyscore: NSA tool collects "nearly everything a user does on the internet". http://www.theguardian.com/world/2013/jul/31/nsa-top-secret-program-online-data Does anyone have a clue how they ...
6
votes
2answers
178 views

Should I test my SSL certificate for “RSA Shared Primes” before using it?

There are several papers from 2012 that say it's possible to factor several moduli by factoring shared primes. The link above includes python sourcecode to verify and test for this fact. Given this ...
3
votes
1answer
422 views

Do I need to keep certificate signing requests and public keys?

I've created an RSA key. Created a CSR. Got it signed and now I have my certificate. It's for a webserver running https. The public key can be generated from the private key, so I guess I don't need ...
1
vote
1answer
310 views

SSL: MITM possible if private key is known? [closed]

If a Man-in-the-middle has the private RSA key of the SSL encryption. It should be possible for the Man-in-the-middle to decode the entire HTTPS datastream right? So, then the encryption is ...