Categories
DNSSEC Infrastructure Security Network Protocols

DNSSEC: A Primer

About DNS The Domain Name System (DNS) was proposed by American computer scientist Paul Mockapetris in 1983, who was at UC Irvine at that time. DNS was created to solve the maintainability and scalability issues of a local hosts file. Today, DNS is one of the core protocols of the Internet, providing a mapping between […]

Categories
Cryptography CTF writeups

PlaidCTF 2015 – Crypto/Parlor2

After going bankrupt last year, the folks behind parlor from last year have decided to set up a new betting service! PlaidCTF 2015 – Crypto/Parlor2 We were given a gambling application where we could choose some modulus [latex] \text{mod }o[/latex]. This modulus would be used by the server to compute a random number [latex] r […]

Categories
Cryptography CTF writeups

PlaidCTF 2015 – Crypto/Lazy

My knapsack brings all the boys to the yard, and they’re like “that crypto is hard” (note: this flag is not in the flag{} format) PlaidCTF 2015 – Crypto/Lazy The challenge provided a few files: pubkey.txt, ciphertext.txt, knapsack.py, utils.py. After inspecting the code, it seems that the contents of ciphertext.txt was encrypted using Merkle-Hallman knapsack (MHK) cryptography, […]