RSA Key Generator - Generate RSA Key Pairs Online

Free online RSA Key Generator - Generate RSA Key Pairs Online tool. No signup required.

Free & instant 100% client-side No signup needed
⚠️ Security Warning: Keep your private key secure and never share it. All key generation happens in your browser - no keys are sent to any server.

Last updated

What is RSA Encryption?

RSA (Rivest-Shamir-Adleman) is a public-key cryptosystem widely used for secure data transmission. It uses a pair of keys: a public key for encryption and a private key for decryption. The public key can be shared freely, while the private key must be kept secret. RSA is fundamental to modern internet security, used in SSL/TLS, SSH, email encryption, and digital signatures.

RSA key pairs consist of two mathematically related keys. Data encrypted with the public key can only be decrypted with the corresponding private key, and vice versa. This asymmetric encryption enables secure communication without sharing secret keys beforehand.

RSA Key Components

RSA Key Structure: 
-----BEGIN RSA PRIVATE KEY-----
MIIEpAIBAAKCAQEA... (Base64 encoded data)
-----END RSA PRIVATE KEY-----

-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA...
-----END PUBLIC KEY-----

How to Use the RSA Key Generator

Step 1: Choose Key Size

Select 2048-bit for standard security (recommended for most uses) or 4096-bit for enhanced security. Larger keys are more secure but slower to generate and use. 2048-bit keys are currently considered secure for most applications.

Step 2: Generate Keys

Click "Generate RSA Keys" to create a new key pair. Generation happens entirely in your browser using cryptographically secure random number generation. No keys are transmitted to any server.

Step 3: Save Keys Securely

Download both keys immediately. Store the private key in a secure location with restricted access. The public key can be shared freely. Never commit private keys to version control or share them via insecure channels.

Step 4: Use Your Keys

Use the public key for encryption or signature verification. Use the private key for decryption or signing. Common uses include SSH authentication, SSL/TLS certificates, and encrypted communication.

Common Use Cases

1. SSH Authentication

Use RSA keys for passwordless SSH login to servers. Add your public key to ~/.ssh/authorized_keys on the server. Use the private key to authenticate without entering passwords.

2. SSL/TLS Certificates

Generate RSA keys for SSL/TLS certificates. The private key stays on your server, while the public key is included in the certificate signed by a Certificate Authority.

3. Code Signing

Sign software releases with your private key. Users verify signatures with your public key, ensuring the software hasn't been tampered with and comes from you.

4. Email Encryption (PGP/GPG)

Use RSA keys for email encryption with PGP or GPG. Share your public key so others can send you encrypted emails that only you can decrypt with your private key.

5. API Authentication

Some APIs use RSA keys for authentication. Generate a key pair, register the public key with the API provider, and use the private key to sign requests.

RSA Key Examples

Example 1: SSH Key Setup

# Add public key to server
cat id_rsa.pub >> ~/.ssh/authorized_keys

# Set correct permissions
chmod 600 ~/.ssh/authorized_keys

# Connect using private key
ssh -i id_rsa user@server.com

Example 2: Encrypt File with Public Key

# Encrypt file
openssl rsautl -encrypt -pubin -inkey public.pem \
  -in file.txt -out file.enc

# Decrypt file with private key
openssl rsautl -decrypt -inkey private.pem \
  -in file.enc -out file.txt

Example 3: Sign Data

# Sign data with private key
openssl dgst -sha256 -sign private.pem \
  -out signature.bin data.txt

# Verify signature with public key
openssl dgst -sha256 -verify public.pem \
  -signature signature.bin data.txt

Example 4: Extract Public Key from Private

# Extract public key from private key
openssl rsa -in private.pem -pubout -out public.pem

# View key details
openssl rsa -in private.pem -text -noout

Example 5: Convert Key Formats

# Convert to PKCS#8 format
openssl pkcs8 -topk8 -inform PEM -outform PEM \
  -in private.pem -out private_pkcs8.pem -nocrypt

# Convert to SSH format
ssh-keygen -f public.pem -i -m PKCS8

Frequently Asked Questions

What key size should I use?
2048-bit keys are currently considered secure for most applications and are the standard. Use 4096-bit keys for enhanced security if you need protection against future threats or handle highly sensitive data.

Frequently Asked Questions

Yes, our Rsa Generator is completely free with no registration required. Use it unlimited times without any restrictions.

Yes, all processing happens locally in your browser. Your data never leaves your device and is not stored on our servers.

No installation needed. The tool works directly in your web browser on any device.

Simply click the generate button and the tool will create a secure, random output instantly. You can customize options if available.

Yes, use the available options to adjust the output format and parameters to match your needs.