Introduction to Security
Interactive demos for CS 360 at UMass Amherst. Pick a topic to explore.
Taught by Eugene Bagdasarian
Asymmetric Encryption
RSA Encryption
Key generation, modular exponentiation, and the math behind public-key encryption. Encrypt and decrypt messages live in the browser.
Diffie-Hellman
See how two parties establish a shared secret over a public channel without ever transmitting the secret itself.
E2E with RSA
Alice sends a message to Bob — a full walkthrough of end-to-end RSA encryption showing each step of the real protocol.
Authentication
Hash Functions
SHA-256
The Merkle-Damgård construction, message schedule, and compression function — with a live demo verified against the browser's native crypto API.
MD5
Four rounds, 64 operations, and a full step-by-step implementation walkthrough — plus a clear explanation of why MD5 is no longer safe to use.
Networking & Security
Network Communication
The OSI model, encapsulation, TCP three-way handshake, IP/MAC addressing — plus an interactive SYN flood attack simulation.
TLS & Heartbleed
How TLS encrypts traffic, the TLS handshake step-by-step, HTTP vs HTTPS — then exploit the Heartbleed bug to leak server memory live.
Certificate Authority
Build your own CA, sign a server certificate, and install it in Chrome. See the chain of trust in action and simulate the ACME protocol.