Asymmetric Encryption
Generate an RSA-OAEP key pair, encrypt text with the public key, and decrypt it exclusively with the private key. Processing stays entirely local to your browser.
1Generate RSA-OAEP Key Pair
You need a cryptographic key pair before you can encrypt or decrypt.
RSA-OAEP Asymmetric Encryption Online
Need to encrypt a payload so that only one specific person or server can read it? Our free online Asymmetric Encryption Tool utilizes the RSA-OAEP algorithm to securely encrypt messages using a Public Key, and decrypt them using the corresponding Private Key.
Local Execution: Cryptographic operations are mathematically intensive. By utilizing the native Web Crypto API, all key generation, encryption, and decryption happen instantly in your browser without ever transmitting your private keys to a server.
Core Features
- Public/Private Key SeparationUnlike symmetric encryption (AES), you can safely share your Public Key with the world. Anyone can use it to encrypt a message, but only you, holding the Private Key, can decrypt it.
- Modern OAEP PaddingThis tool uses Optimal Asymmetric Encryption Padding (OAEP), the modern standard that protects against chosen-ciphertext attacks commonly found in older RSA implementations (like PKCS#1 v1.5).
- Built-in Key GeneratorDon't have an RSA key pair? You can instantly generate secure 2048-bit or 4096-bit RSA keys directly within the tool to test the encryption/decryption flow.
How Asymmetric Encryption Works
1. The Sender
Takes the recipient's Public Key and encrypts the plaintext message.
2. The Recipient
Uses their mathematically linked Private Key to decrypt the ciphertext back to plaintext.
Note on Payload Size: RSA encryption is computationally heavy and strictly limited by key size (a 2048-bit key can only encrypt about 214 bytes of data). It is typically used to encrypt Symmetric Keys (AES), which are then used to encrypt the actual large payload.
Related Tools
RSA/EC Key GeneratorGenerate asymmetric public/private key pairs in PEM and JWK formats.Symmetric EncryptionEncrypt large files and texts using a single AES password.Hash GeneratorCreate one-way cryptographic digests of your text.JWT ValidatorVerify a JSON Web Token signature using an RSA public key.
Categories
Frequently Asked Questions
What is the difference between Symmetric and Asymmetric encryption?
Symmetric encryption uses one key (a password) to both encrypt and decrypt data. It is very fast and can handle large amounts of data. Asymmetric encryption uses two mathematically linked keys: a Public key to encrypt, and a Private key to decrypt. It solves the problem of securely sharing a secret over an untrusted network.
Why can't I encrypt long texts with RSA?
RSA relies on factoring large prime numbers. The algorithm limits the maximum amount of plaintext to the size of the key itself, minus the overhead of the padding scheme. For a standard 2048-bit key using OAEP padding, the maximum plaintext length is exactly 214 bytes. To encrypt larger data, use RSA to encrypt a symmetric AES key, and then use that AES key to encrypt the large data (this is called "Hybrid Encryption").