RSA key pair generator

Generate a new random RSA private and public pem certificate key pair.

Enable JavaScript to use the interactive tool. The guide below explains how it works.

RSA Key Pair Generator

What it does

The RSA Key Pair Generator is a secure, browser-based utility for creating asymmetrical cryptographic keys. It generates a Public Key and a Private Key in the standard PEM format. You can customize the strength of the keys by adjusting the bit length, ranging from 256 bits for testing up to 16,384 bits for extreme security.

Why someone uses it

• SSH Authentication: Generating keys to securely log into remote servers without a password.
• Secure Communication: Setting up asymmetrical encryption where anyone can use your Public Key to encrypt data that only your Private Key can decrypt.
• Digital Signatures: Creating keys to sign software or documents, allowing others to verify that the content hasn't been tampered with.
• Local Development: Quickly generating keys for testing HTTPS, JWT signing, or encrypted database connections.

Step-by-step instructions

1. Choose Bit Length: Enter the number of bits in the Bits field. The industry standard is 2048, while 4096 is used for higher security. The value must be a multiple of 8.
2. Generate Keys: The tool generates keys automatically. If you want a different set, click Refresh key-pair.
3. Copy Public Key: Copy the top block of text. This is what you share with others or upload to servers (e.g., your authorized_keys file).
4. Copy Private Key: Copy the bottom block. Warning: Keep this key secret and never share it.

Examples

• Standard Web Use: Set bits to 2048 for a balance of speed and security.
• Hardened Server Access: Set bits to 4096 for sensitive infrastructure.
• Quick Testing: Set bits to 1024 for fast generation during development (do not use in production).

FAQs

• Is this safe to use? Yes. The keys are generated locally in your browser using the Web Crypto API. Your private key is never transmitted to any server.
• Which bit length is best? For most modern applications, 2048 bits is the recommended minimum. 4096 bits is more secure but results in slower encryption/decryption operations.
• What does PEM format mean? It stands for "Privacy-Enhanced Mail". It is a text-based format that encodes binary cryptographic data into a Base64 string surrounded by header and footer markers.

Common mistakes

• Exposing the Private Key: The most common mistake is accidentally committing your private key to a public repository like GitHub or sharing it in a support ticket.
• Using Bit Lengths too Low: Using 512 or 1024 bits for production data, which can be cracked relatively easily by modern hardware.
• Confusion between Keys: Using the Private Key where the Public Key is required (e.g., on a public server).

Use cases

• GitHub/GitLab Setup: Creating an SSH key to push code securely.
• JWT Signing: Generating the RS256 keys required for signing and verifying JSON Web Tokens.
• Encryption Tools: Providing keys for tools that encrypt sensitive files or messages.

Related tools

• Encryption: For encrypting and decrypting text using various algorithms.
• BIP39 Generator: For creating secure mnemonic phrases used in cryptocurrency and wallet security.
• Hash Text: For generating one-way hashes to verify data integrity.