How to find Private/RSA Keys

[MarceloQuad]

Hello friends,
I have read that the RSA is a method for encrypting data using a public key and private key. I am newbie in this section, so not having much knowledge about the RSA. I am posting here, so that someone over out there would help me in clearing the doubt. So, please provide some useful information about the same.!!

[yuppicide]

As you know that RSA is a method for encrypting data using a public key and private key. This method is widely used today, particularly in banking, shopping on the internet or just to sign and / or encrypt a message. A RSA key is an integer, and when we speak of n-bit RSA key it is in fact an RSA key, expressed in binary, is n bits long. The longer the key, the greater the number of possible keys is important: we can create more than 512 key bits of 8-bit key. Nowadays, it mainly uses keys 1024 and 2048 bits. There are so many possible keys.

[Pikachoo]

The strength of the RSA algorithm is based on the simple fact that it is very long to find the prime factors of a given integer. But these factors are needed to break a message encrypted with RSA. For example, an RSA private key of 1024 bits, it will not take you less than 1500 years on a very good machine! To break an RSA key, you have to work full of machines at the same time, and still is not guaranteed. You can always try on your machine with small keys.

[KaramChand]

The RSA is not an alternative system DES (secret key) and replace it, which it supplements (like any other encryption for bulk data encryption) and is used with the DES system for creating a secure means of communication. The RSA adds two important functions not provided by the DES system: secure key exchange without prior exchange of secret keys and digital signatures.

[Jarvis]

To encrypt messages, using RSA and DES in combination as follows :

1. It encrypts the message with a randomly selected DES key.
2. Before sending in a low-secure DES key is encrypted using the RSA.
3. Are sent together, the message DES encryption and DES key encrypted via RSA.

One might ask the reason why the system is not used RSA to encrypt the message directly and avoid the use of the DES. While it may be applied to short messages, the DES (or another encryption system) is preferable in the case of a long message because it is much faster than RSA.

[Sanith]

The private key (in / root / .ssh / id_rsa) remains on the server and should never be revealed, and the public key (in / root / .ssh / id_rsa.pub) is that the machines that want to connect (client) must use in order to authenticate.

<SPAN onmouseover="_tipon(this)" onmouseout="_tipoff()">
<SPAN class="google-src-text" style="direction: ltr; text-align: left">
Pouzy:~ ls /root/.ssh</SPAN> Pouzy: ~ ls / root / .ssh</SPAN>  
2	<SPAN onmouseover="_tipon(this)" onmouseout="_tipoff()">
<SPAN class="google-src-text" style="direction: ltr; text-align: left">
id_rsa  id_rsa.pub  known_hosts</SPAN>
 id_rsa id_rsa.pub known_hosts</SPAN>

[Shen]

If the local machine is running Linux, you will have no problems and a simple ssh user @ ip_distante using the key needed!

<SPAN onmouseover="_tipon(this)" onmouseout="_tipoff()"><SPAN class="google-src-text" style="direction: ltr; text-align: left">Pouzy# ssh pouzy@machine_distante</SPAN> Pouzy @ host # ssh Pouzy</SPAN>  
2	<SPAN onmouseover="_tipon(this)" onmouseout="_tipoff()"><SPAN class="google-src-text" style="direction: ltr; text-align: left">Authenticating with public key "openssh-key"</SPAN> Authenticating with public key "openssh-key"</SPAN>  
3	<SPAN onmouseover="_tipon(this)" onmouseout="_tipoff()"><SPAN class="google-src-text" style="direction: ltr; text-align: left">Passphrase for key "openssh-key":</SPAN> Passphrase for key "openssh-key":</SPAN>