Question 1

What is an RSA key pair?

Accepted Answer

RSA is an asymmetric encryption algorithm that uses two mathematically linked keys: a public key that anyone can use to encrypt data or verify signatures, and a private key that only the owner holds to decrypt data or sign messages. The security comes from the difficulty of factoring the product of two large prime numbers.

Question 2

What RSA key size should I use?

Accepted Answer

2048 bits is the current minimum recommended by NIST and is acceptable through 2030. 3072 bits provides a comfortable safety margin and 4096 bits is the most secure mainstream option, though it is slower. For new production systems, 3072 or 4096 bits is recommended.

Question 3

Are the generated keys private?

Accepted Answer

Yes. The keys are generated entirely in your browser using the Web Crypto API. The private key never leaves your device — it is not uploaded to any server, logged, or stored. Always keep your private key safe and never share it.

Question 4

What can I use RSA keys for?

Accepted Answer

RSA keys are used for TLS/SSL certificates, SSH authentication (though SSH typically uses ed25519 or RSA-SHA2), JWT signing (RS256), email encryption (PGP/GPG), code signing, document signing and protecting symmetric keys in hybrid encryption schemes.

Question 5

Why does generation sometimes take a few seconds?

Accepted Answer

Generating an RSA key requires finding large prime numbers through repeated random testing. 4096-bit keys can take several seconds even on modern hardware. The browser is doing real cryptographic work, not loading anything from a network.