How Is A Private Key Generated From A Public Key

16.04.2020
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  1. Create A Public Key From Private Key
  2. How Is A Private Key Generated From A Public Key System
  3. Generate Private And Public Key

Y This option will read a private OpenSSH format file and print an OpenSSH public key to stdout. Specify the private key with the -f option, yours might be dsa instead of rsa. The name of your private key probably contains which you used. The newly generated public key should be the same as the one you generated before. Jul 23, 2011 The key difference between Public key and Private Key is that if the public key is the locking key, then it can be used to send private communication (i.e. To preserve confidentiality) while If the private key is the locking key, then the system can be used to verify documents sent by the holder of the private key (i.e. To preserve authenticity).

Several tools exist to generate SSH public/private key pairs. The following sections show how to generate an SSH key pair on UNIX, UNIX-like and Windows platforms.

Generating an SSH Key Pair on UNIX and UNIX-Like Platforms Using the ssh-keygen Utility

UNIX and UNIX-like platforms (including Solaris and Linux) include the ssh-keygen utility to generate SSH key pairs.

Public
To generate an SSH key pair on UNIX and UNIX-like platforms using the ssh-keygen utility:

Create A Public Key From Private Key

Generate
  1. Navigate to your home directory:
  2. Run the ssh-keygen utility, providing as filename your choice of file name for the private key:

    The ssh-keygen utility prompts you for a passphrase for the private key.

  3. Enter a passphrase for the private key, or press Enter to create a private key without a passphrase:

    Note:

    While a passphrase is not required, you should specify one as a security measure to protect the private key from unauthorized use. When you specify a passphrase, a user must enter the passphrase every time the private key is used.

    The ssh-keygen utility prompts you to enter the passphrase again.

  4. Enter the passphrase again, or press Enter again to continue creating a private key without a passphrase:
  5. The ssh-keygen utility displays a message indicating that the private key has been saved as filename and the public key has been saved as filename.pub. It also displays information about the key fingerprint and randomart image.

Generating an SSH Key Pair on Windows Using the PuTTYgen Program

How Is A Private Key Generated From A Public Key System

The PuTTYgen program is part of PuTTY, an open source networking client for the Windows platform.

Generate Private And Public Key

To generate an SSH key pair on Windows using the PuTTYgen program:
  1. Download and install PuTTY or PuTTYgen.

    To download PuTTY or PuTTYgen, go to http://www.putty.org/ and click the You can download PuTTY here link.

  2. Run the PuTTYgen program.
  3. Set the Type of key to generate option to SSH-2 RSA.
  4. In the Number of bits in a generated key box, enter 2048.
  5. Click Generate to generate a public/private key pair.

    As the key is being generated, move the mouse around the blank area as directed.

  6. (Optional) Enter a passphrase for the private key in the Key passphrase box and reenter it in the Confirm passphrase box.

    Note:

    While a passphrase is not required, you should specify one as a security measure to protect the private key from unauthorized use. When you specify a passphrase, a user must enter the passphrase every time the private key is used.

  7. Click Save private key to save the private key to a file. To adhere to file-naming conventions, you should give the private key file an extension of .ppk (PuTTY private key).

    Note:

    The .ppk file extension indicates that the private key is in PuTTY's proprietary format. You must use a key of this format when using PuTTY as your SSH client. It cannot be used with other SSH client tools. Refer to the PuTTY documentation to convert a private key in this format to a different format.
  8. Select all of the characters in the Public key for pasting into OpenSSH authorized_keys file box.

    Make sure you select all the characters, not just the ones you can see in the narrow window. Generate public key putty. If a scroll bar is next to the characters, you aren't seeing all the characters.

    Linux generate ssh key for another user. By November 2, 2018 November 1, 2018We often use ssh-copy-id to copy ssh keys from our local computers to RHEL servers in order to connect without typing in a password.

  9. Right-click somewhere in the selected text and select Copy from the menu.
  10. Open a text editor and paste the characters, just as you copied them. Start at the first character in the text editor, and do not insert any line breaks.
  11. Save the text file in the same folder where you saved the private key, using the .pub extension to indicate that the file contains a public key.
  12. If you or others are going to use an SSH client that requires the OpenSSH format for private keys (such as the ssh utility on Linux), export the private key:
    1. On the Conversions menu, choose Export OpenSSH key.
    2. Save the private key in OpenSSH format in the same folder where you saved the private key in .ppk format, using an extension such as .openssh to indicate the file's content.