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Cryptography Club
@ Princeton University
Every Tuesday at 4:30pm in Frist 309. Join our Signal chat.
Upcoming
03/18: ???
Stay tuned...
Past
02/25: Privacy Enchancing Technologies
Ever wondered what a VPN actually does? Or what Tor is? Is Incognito mode effective? Ever heard of a certificate authority? Let's learn about internet cryptography together at this week's plaintext! (Slides)
02/11: Secret Sharing
With secret sharing, you can split a secret into multiple parts and share them with other people. Each person that gets a part won't learn the secret but if enough of them combine their individual parts, they can recover the secret! Super cool! This is actually used in practice for missile and nuclear launch codes to keep them secure from misuse! Come learn how it all works at p l a i n t e x t this week! (Slides)
01/28: Linear Cryptanalysis
Welcome to Season 2 of plaintext! To kick off the semester, we will be diving into linear cryptanalysis. Come to learn about this powerful technique for attacking symmetric ciphers, and explore how statistical biases in encryption can be exploited to recover secret keys. (Slides)
12/03: Fully Homomorphic Encryption
Would it be possible to devise an encryption scheme such that adding two ciphertexts would correspond to an encryption of the addition of both the plaintexts? Or does this necessarily compromise on security? To answer these questions, come learn about fully homomorphic encryption, an idea first formulated in 1978, but one that has now become a topic of cutting edge research in the 21st century! (Slides)
11/19: Randomness (and lack thereof)
Almost every cryptosystem we've discussed, or will discuss, presupposes that you can generate a "random number". But how do you do this with inherently deterministic machines, anyway? In this presentation we'll discuss randomness in cryptography from single numbers to entire streams, and see how some systems can fall short. (Slides)
11/12: Graduate Talk on Quantum Cryptography!
Barak Nehoran, Princeton CS PhD candidate, will be giving an introduction to quantum cryptography, including: pseudorandom quantum states/unitaries, one-way quantum state generators, quantum commitments, and more! Quantum computing supercharges cryptography, and even if P=NP, it is possible to build secure quantum-based cryptosystems! Come and learn how!
11/05: CTF Cryptography Special feat. OrangeHat
This week we'll be teaming up with the OrangeHat Cybersecurity Collective to host a hands-on introduction to CTF-style cryptography challenges! Don't forget your PC!
10/29: Zero Knowledge Proofs: A Deep Dive
You might have heard the acronym zkSNARK before, but what does it really mean? In this exciting plaintext presentation, we will be introducing the awesome field of zero knowledge cryptography. It will be almost completely math free, covering sigma protocols, the Fiat-Shamir transform, R1CS, Circom, and more! (Slides)
10/22: Discrete Logarithm Problem and Pohlig-Hellman
The Diffie-Hellman system enables ciphers like AES to encrypt data across the internet, from protocols like HTTPS to SSH. This week, we'll learn about the Discrete Logarithm Problem and how its difficulty allows two parties to agree on a secret key without ever sending it. With more modular arithmetic and a little group theory, we'll see how Pohlig-Hellman can make hard problems easy, and leave things exposed. (Slides) (Photo)
10/01: Web3 Security Special, feat. PBC
You don't want to miss this special collaboration between plaintext and Princeton Blockchain Club! We'll be introducing smart contract security fundamentals through the hands-on platform Ethernaut - don't forget your PC! (Slides)
09/24: The BB84 Protocol and Quantum Cryptography
Quantum computing and quantum technology are poised to take the world by storm in the coming decades. Learn more about the fundamentals behind quantum cryptography as we delve into qubits, quantum entanglement, and the famous BB84 protocol -- a cryptographic protocol where the security guarantees come from the laws of physics! (Slides)
09/17: AES-ECB and Padding Oracle Attacks
The block cipher AES has withstood cryptanalytic attacks for ages, and is being used everywhere right now! However, like all block ciphers, AES requires a "mode of operation" to work properly. This is where things go wrong... At plaintext this week, you'll learn about AES, the ECB mode of operation, the PKCS#1 scheme, and the ECB padding oracle attack! (Slides)
09/10: RSA and Coppersmith's Method
We can attack RSA, the most important encryption system in the world, using linear algebra! This technique is called Coppersmith's method and is incredibly versatile. Come to the inaugural plaintext meeting for an introduction to RSA, followed by a deep dive into lattices, the LLL algorithm, modular polynomials, Estonian ID cards, and more! (Slides) (Demo .ipynb) (Photo)