PUBLIC File – What is .public file and how to open it?

Definition and Usage

A PUBLIC file is a text file containing an OpenSSL Public Key. This key is used for encrypting data securely. OpenSSL, an open-source cryptography toolkit, generates and manages these public keys for secure data transfer. The PUBLIC file typically includes the key information in PEM format (Privacy Enhanced Mail) and begins with the “—–BEGIN PUBLIC KEY—–” header. The key is represented as a series of base64-encoded characters followed by a “—–END PUBLIC KEY—–” footer.

Importance in Secure Communication

Public keys play a crucial role in public-key cryptography, where two keys are used – a public key and a private key. The PUBLIC file contains the public key, which is widely distributed and not kept secret. The corresponding private key, which is securely protected, is used to decrypt data encrypted using the public key. This asymmetric approach ensures that only the intended recipient can decrypt the message, guaranteeing the confidentiality of sensitive information. The PUBLIC file allows recipients to verify the authenticity of the sender’s signature and to securely receive encrypted data.

Using OpenSSL Command Line

OpenSSL, an open-source cryptography toolkit, provides a command-line tool to open and display PUBLIC files. To do this, follow these steps:

1. Open your command prompt or terminal window.
2. Navigate to the directory containing the PUBLIC file.
3. Enter the command: openssl rsa -text -in filename.PUBLIC

Replace “filename.PUBLIC” with the actual name of your PUBLIC file. This command will display the contents of the PUBLIC file, including the public key information in a human-readable format.

Using Third-Party Software

If you prefer a more user-friendly interface, there are third-party software applications that can open and view PUBLIC files. These applications typically provide a graphical interface that allows you to easily navigate and inspect the contents of the file. Some popular options include:

• OpenSSL Tool Kit
• PuTTYgen
• Certificate Manager

OpenSSL Public Key (PUBLIC)

The PUBLIC file extension is associated with OpenSSL, an open-source cryptographic software library. It contains a public key used in public-key cryptography, a method of encrypting and decrypting data using a pair of keys: a public key and a private key. The public key is used to encrypt data, while the private key is used to decrypt it.

PUBLIC files are typically used to distribute the public key of an individual or organization for secure communication. For example, if you want to send encrypted email to someone, you can provide them with your PUBLIC file, which contains your public key. They can then use your public key to encrypt the email, and only you (who possess the corresponding private key) will be able to decrypt it.

Other Extensions