Welcome πŸ‘‹

Hello, I’m Hyunsik Jeong a.k.a. RBTree. I mainly write articles related to cryptography, reverse engineering, and other CTF/security-related stuffs here.

μ „λ¬Έμ—°κ΅¬μš”μ›μ„ μœ„ν•œ ν›ˆλ ¨μ†Œ μ€€λΉ„λ¬Ό 및 팁

2022λ…„ 7μ›” 7일에 ν›ˆλ ¨μ†Œμ— μž…μ†Œν•΄μ„œ 7μ›” 28일에 ν‡΄μ†Œν–ˆμŠ΅λ‹ˆλ‹€. λ‹€ν–‰νžˆλ„ 쒋은 μ‚¬λžŒλ“€κ³Ό 같은 λΆ„λŒ€μ—μ„œ μƒν™œν•΄μ„œ 잘 지낼 수 μžˆμ—ˆμŠ΅λ‹ˆλ‹€. 이 κΈ€μ—μ„œλŠ” 개인적으...

2022-07-31 Β· 6 min Β· RBTree

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. 😒😒😒 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 Β· 1 min Β· RBTree

SageMath script for AES-GCM challenges

There was an interesting challenge about AES-GCM in LINE CTF 2022, called ’lazy STEK.' I’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 Β· 2 min Β· RBTree

2021 회고

νž˜λ“€μ—ˆλ˜ ν•΄ 말할 μˆ˜λŠ” μ—†λŠ” νž˜λ“  일이 정말 λ§Žμ•˜λ˜ 해인 것 κ°™μŠ΅λ‹ˆλ‹€. 특히 8μ›” 달 μ―€λΆ€ν„° μ—°λ‹¬μ•„μ„œ 괴둜운 일이 λ§Žμ•˜λ˜ 것 κ°™μŠ΅λ‹ˆλ‹€. 괴둜운 일이 λ§Žμ•„μ§€λ‹ˆ ν‰μ†Œμ— 쒋은 λͺ¨μŠ΅...

2021-12-31 Β· 2 min Β· RBTree

Attacking a Variant of the RSA Cryptosystem

μ„œλ‘  이번 글은 μ €λ²ˆ λ‹¬μ˜ 글에 μ΄μ–΄μ„œ pbctf 2021λ₯Ό μΆœμ œν•˜λ©΄μ„œ μ‚¬μš©ν•œ λ…Όλ¬Έ ν•˜λ‚˜λ₯Ό λ¦¬λ·°ν•˜λ €κ³  ν•©λ‹ˆλ‹€. 이 논문은 Yet Another RSAλΌλŠ” 문제둜 μž‘μ„±ν•˜κ²Œ λ˜μ—ˆμŠ΅λ‹ˆλ‹€. ν•΄λ‹Ή λ…Ό...

2021-11-21 Β· 7 min Β· RBTree