A public key/private key keypair, is generated by using special programs according to the use of the keypair. If it’s ssh, it is described in other answers. If it’s a cryptocurrency keypair, every cryptocurrency has it’s own software to do this. The private key is usually not generated first. In general, they're generated at the same time. For some schemes, the public key can be derived from the private key, but this doesn't always hold, and that will depend on specific properties of the particular public-key scheme.
To perform the following actions for Windows or Linux, you must have OpenSSL installed on your system.
Generating the Private Key -- Windows
In Windows:
1. Open the Command Prompt (Start > Programs > Accessories > Command Prompt).
2. Navigate to the following folder:
C:Program FilesListManagertclwebbincerts
3. Type the following:
openssl genrsa -out rsa.private 1024
4. Press ENTER. The private key is generated and saved in a file named 'rsa.private' located in the same folder.
NOTE The number '1024' in the above command indicates the size of the private key. You can choose one of five sizes: 512, 758, 1024, 1536 or 2048 (these numbers represent bits). The larger sizes offer greater security, but this is offset by a penalty in CPU performance. We recommend the best practice size of 1024.
Generating the Public Key -- Windows
1. At the command prompt, type the following:
Public And Private Key Examples
openssl rsa -in rsa.private -out rsa.public -pubout -outform PEM
2. Press ENTER. The public key is saved in a file named rsa.public located in the same folder.
Generating the Private Key -- Linux
1. Open the Terminal.
2. Navigate to the folder with the ListManager directory.
3. Type the following:
How Are Public And Private Keys Generated In Kenya
openssl genrsa -out rsa.private 1024
4. Press ENTER. The private key is generated and saved in a file named 'rsa.private' located in the same folder.
Generating the Public Key -- Linux
1. Open the Terminal.
2. Type the following:
openssl rsa -in rsa.private -out rsa.public -pubout -outform PEM
2. Press ENTER. The public key is saved in a file named rsa.public located in the same folder.