RS256 vs HS256?

Difficulty: 6/10

JWT signing, algorithm choice, key management

RS256 uses asymmetric keys (private + public) for signing, ideal for distributed systems; HS256 uses a shared secret, simpler but less secure for multi-service environments.

HS256 (HMAC with SHA-256) uses a single secret key to both sign and verify tokens. It is fast and simple, but the secret must be shared among all services that validate tokens. If the secret is compromised, an attacker can forge tokens. RS256 (RSA with SHA-256) uses a private key to sign tokens and a public key to verify them. This allows the authentication server to keep the private key secret, while any service can obtain the public key (e.g., via JWKS). RS256 is the preferred choice for microservices because it enables secure key distribution without sharing sensitive secrets.

Key Differences

1
HS256: Symmetric, single secret, faster, risk of secret leakage, harder to rotate.
2
RS256: Asymmetric, public/private key pair, safer for microservices, supports key rotation via JWKS.
3
Recommendation: Use RS256 in production microservices; HS256 is acceptable for internal, trusted services.

Scenario Questions

0-2 years experience

Follow-up Questions