RSA Key Generator & Encrypt/Decrypt

1024, 2048, and 4096 bits. 2048 is the recommended balance of security and performance; 1024 is no longer advised for production; 4096 is stronger but slower.

Padding first: PKCS#1 v1.5 and OAEP don't interoperate, and mismatched ends simply fail to decrypt. Then confirm the keys are a matched pair and the ciphertext is intact; if it still misbehaves, reproduce with a minimal sample (short text plus fixed options) to tell an input problem from an option-combination problem.

Not a good fit. RSA is asymmetric — public key encrypts, private key decrypts — suited to key exchange and signatures, but it has a per-block size cap and is slow. AES is symmetric, fast, and unlimited in length. The right pattern for large files is hybrid: AES encrypts the data while RSA only protects that AES key. For the symmetric half, use the AES tool on this site.

This tool is aimed at teaching and integration demos; real systems should pick libraries and parameters per a security baseline, and it is no substitute for a professional assessment. Neighboring tools split the work: bcrypt for password hashing, certificate-decoder for inspecting certificates; on odd output, reproduce minimally first, then move to the next tool.