Functional Encryption
An introduction to functional encryption, with a focus on registered FE for circuits and the security model behind bounded collusion.
Saro
K17 CTF Non-AI Division Crypto writeup
A CTF writeup on abusing per-block signatures and CBC encryption/decryption oracles to forge an admin JSON message.
Decomposed LWE: From Gadget Decomposition to the Formal Assumption
An intuitive and formal introduction to Decomposed LWE, from gadget decomposition to the structured distinguishing assumption.
Secret Sharing and Threshold Cryptography: From Shamir to T-out-of-N
A learning note on secret sharing, Shamir's construction, Lagrange interpolation.
Introduction to Elliptic Curve Cryptography
Elliptic-curve arithmetic, ECDLP, ECDH/ECDSA, and classic attacks.