Perhaps askubuntu is not the best place for this question, however, this pertains to all linux systems, including Ubuntu. After the Snowden leaks, a lot of people have questioned the integrity of RSA keys. Some claim that there is a backdoor in the RSA algorithm. If that is true, than virtually every server on the planet is at risk. Of course, there are DSA keys, but we are told that 1024 bit keys are no longer strong enough to offer reliable protection against today’s computing power.
The openssl library has many, many ciphers. OpenVPN can utilize quite a few of them, so why can't ssh use more than just RSA or DSA? And why are DSA keys limited to 1024 bits..? Shouldn't we be looking towards moving away from RSA, and towards a more secure cipher, that does not potentially have an NSA backdoor encoded in it? Another things I find odd is that when I generate a 4096 bit RSA key, it happens in seconds. But when I generate a 4096 bit GPG key, it can take quite a while. That tells me that maybe the randomness of RSA is not so random...?
Am I missing something? It would appear to me that the entire Linux community is relying on a potentially insecure cipher for protection, myself included. Why aren't there more ciphers to choose from? What gives?
man ssh-keygen
:-t type Specifies the type of key to create. The possible values are “rsa1” for protocol version 1 and “dsa”, “ecdsa”, “ed25519”, or “rsa” for protocol version 2.