Cyber security · Interactive model

Alice, Bob & Eve

Alice wants to send Bob a message, but Eve is on the wire between them. Public-key cryptography gives Alice two separate tools: encrypt with Bob's public key so only Bob can read it, and sign with her own private key so Bob knows it's really from her and untampered. They're different jobs. Compose a message, choose your protections, and see exactly what Eve can do with what you leave unguarded.