Writeup for Crypto Problems in 5spaceCTF 2020

Writeup for 3 crypto challenges in “第五空间” 智能安全大赛 2020 (2020-06-24 09:00 +12h).
- (easy) rosb: RSA common modulus attack
- (medium) UnSafeAES: AES-GCM nonce reuse && forbidden attack
- (interesting) tinysocks: redirect attack on Shadowsocks stream ciphers.

Why Ethereum Has Three Trees

Ethereum has three trees: the state tree, the transaction tree, and the receipt tree. Why do we need three trees? Can we discard one of them? In this post, we explore the principles of the construction of the three trees.