Pointers, endianness, and remembering how the stack grows (downwards).
Smashing the stack for fun and profit. RIP instruction pointer.
ASLR, Stack Canaries, and DEP/NX. Trying to patch the holes in C.
Block ciphers, AES, CBC mode. Why ECB mode leaves a visible penguin.
RSA, Diffie-Hellman, and prime factorization. Math keeping our secrets safe.
SHA-256, HMACs, and verifying that Bob actually sent the message.
Public Key Infrastructure (PKI) and why you shouldn't ignore browser warnings.
Same-Origin Policy. The browser trying its best to not let tabs steal your bank info.
Cross-Site Scripting and Bobby Tables. Never trust user input.
Cross-Site Request Forgery and session hijacking. Secure your cookies.
Packet sniffing, ARP spoofing, and BGP hijacking. The internet is built on duct tape.
Firewalls, NIDS, and port scanning. Keeping the bad packets out.
Worms, botnets, and ransomware. Analyzing the payload without infecting yourself.