## Some Thoughts About the Past, the Present, and the Future —— 2020.06.07

A plain record of the first half year of 2020, some feelings about the first internship, and a dazed plan.

## 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.

## Writeup for De1CTF2020 by X1cT34m

Writeup for several problems in De1CTF 2020 by X1cT34m.

## Writeup for Crypto Problems in HufuCTF 2020

Writeup for 3 crypto challenges in 虎符CTF 2020 (2020-04-19 09:00 +8h).
- (easy) GM: recover every bit of RSA message by using legendre symbol
- (medium) mceliece: break a Mceliece cryptosystem with small parameters
- (easy) pell: solve specified pell equations.

## A Tour of Go

How I pick up Golang in just one day.

## Writeup for Crypto Problems in VolgaCTF 2020

Writeup for 3 easy crypto challenges of VolgaCTF 2020.

## Case Study: Trivial Attack and Nontrivial Attacks against DSS

In this post, we give a concise study of several attaks against DSS, including, reused $k$, $k$ generated via LCG, and lattice attack against short $k$.