## Posts from the Samsung Software Membership blog

Finally, I copied my posts from the Samsung Software Membership blog. Those are not translated yet. I hope I can finish the translation someday. ๐ข๐ข๐ข Digital Signatures and Nonce Reuse Shellcoding and Bitflip Conjecture Smooth numbers and Factorization On Factoring Given Any Bits Forgery Attack on ElGamal Signatures How to build WebAssembly apps with Rust AntiVirus Oracle Singular Elliptic Curves Anomalous Elliptic Curves SMT Solvers in CTF -...

2022-04-26 ยท 1 min ยท RBTree

## SageMath script for AES-GCM challenges

There was an interesting challenge about AES-GCM in LINE CTF 2022, called โlazy STEK.' Iโm not gonna talk about the challenge itself. When I was solving this challenge, I realized that I did not save a script to convert between byte blocks and $\mathbb{F}_{2^{128}}$ elements in SageMath. As it is a bit confusing to understand how the conversion works, I share my script with the solution of lazy STEK here for someone struggling with this problem....

2022-03-27 ยท 2 min ยท RBTree

## 2021 ํ๊ณ

ํ๋ค์๋ ํด ๋งํ  ์๋ ์๋ ํ๋  ์ผ์ด ์ ๋ง ๋ง์๋ ํด์ธ ๊ฒ ๊ฐ์ต๋๋ค. ํนํ 8์ ๋ฌ ์ฏค๋ถํฐ ์ฐ๋ฌ์์ ๊ดด๋ก์ด ์ผ์ด ๋ง์๋ ๊ฒ ๊ฐ์ต๋๋ค. ๊ดด๋ก์ด ์ผ์ด ๋ง์์ง๋ ํ์์ ์ข์ ๋ชจ์ต...

2021-12-31 ยท 2 min ยท RBTree

## Attacking a Variant of the RSA Cryptosystem

์๋ก  ์ด๋ฒ ๊ธ์ ์ ๋ฒ ๋ฌ์ ๊ธ์ ์ด์ด์ pbctf 2021๋ฅผ ์ถ์ ํ๋ฉด์ ์ฌ์ฉํ ๋ผ๋ฌธ ํ๋๋ฅผ ๋ฆฌ๋ทฐํ๋ ค๊ณ  ํฉ๋๋ค. ์ด ๋ผ๋ฌธ์ Yet Another RSA๋ผ๋ ๋ฌธ์ ๋ก ์์ฑํ๊ฒ ๋์์ต๋๋ค. ํด๋น ๋ผ...

2021-11-21 ยท 7 min ยท RBTree

## Breaking Combined Multiple Recursive Generators

์๋ก  10์ ์ค์ ์ ๊ฐ ์ํ CTF ํ perfect blue์์ pbctf 2021์ ์ฃผ์ตํ์ต๋๋ค. CTF๋ฅผ ์ค๋นํ๋ฉด์ ๋ค์ํ ์ํธํ ๋ผ๋ฌธ๋ค์ ์ฝ์ด๋ณด์๋๋ฐ, ๊ทธ ์ค์์๋ ์ฐธ๊ณ ํ ๋งํ ํฅ...

2021-10-24 ยท 5 min ยท RBTree