https://blog.soreatu.com/ Soreat_u's personal blog Hugo 0.152.2 https://gohugo.io/ en [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Thu, 21 May 2026 14:21:12 +1000 https://blog.soreatu.com/posts/2025-12-tas-stanley-trip/ https://blog.soreatu.com/posts/2025-12-tas-stanley-trip/ Thu, 01 Jan 2026 23:56:11 +1100 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) [2025.12.25~26] 🇦🇺塔州Stanley小镇两日游 Travel https://blog.soreatu.com/posts/writeup-for-3-blockchain-challs-in-sekaictf-2024/ https://blog.soreatu.com/posts/writeup-for-3-blockchain-challs-in-sekaictf-2024/ Thu, 29 Aug 2024 15:29:55 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) I played in the SekaiCTF 2024 to learn something on blockchain and solved 3 out of 4 blockchain challenges (Play to Earn, ZOO, and survive), here’s the writeup. Writeup https://blog.soreatu.com/posts/writeup-for-tree-and-lightbook-in-crewctf-2024/ https://blog.soreatu.com/posts/writeup-for-tree-and-lightbook-in-crewctf-2024/ Wed, 07 Aug 2024 00:58:53 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) I played solo in the CrewCTF 2024 for fun and solved (all) 2 blockchain challenges, here&rsquo;s the writeup. Writeup https://blog.soreatu.com/posts/us-b2-visa-appointment/ https://blog.soreatu.com/posts/us-b2-visa-appointment/ Tue, 23 Jul 2024 17:40:53 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) 美签B2武汉面签实录 Travel https://blog.soreatu.com/posts/2024-06-xiamen-one-night/ https://blog.soreatu.com/posts/2024-06-xiamen-one-night/ Thu, 27 Jun 2024 18:35:03 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) [2024.06.24~25] 厦门一夜快闪游（多图预警） Travel https://blog.soreatu.com/posts/blockchain-remote-rpc-serialization-endpoint-risk/ https://blog.soreatu.com/posts/blockchain-remote-rpc-serialization-endpoint-risk/ Sat, 06 Apr 2024 11:39:31 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) An inherent security risk that I discovered within the remote RPC serialization endpoints of several emerging blockchains. Blockchain https://blog.soreatu.com/posts/2023-year-end-summary/ https://blog.soreatu.com/posts/2023-year-end-summary/ Sun, 18 Feb 2024 01:02:17 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) 2023年终总结 Just a Transient Thought https://blog.soreatu.com/posts/cloud-gaming/ https://blog.soreatu.com/posts/cloud-gaming/ Sat, 08 Oct 2022 00:08:01 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) A cloud gaming solution by Parsec. Others https://blog.soreatu.com/posts/analysis-of-cve-2022-21449-bypass-java-signature-check-by-two-zeros/ https://blog.soreatu.com/posts/analysis-of-cve-2022-21449-bypass-java-signature-check-by-two-zeros/ Fri, 29 Apr 2022 00:21:40 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Analyse CVE-2022-21449 by diving into the source code. Cryptography https://blog.soreatu.com/posts/notes-on-black-hat-usa-2021-talk-timeless-timing-attack/ https://blog.soreatu.com/posts/notes-on-black-hat-usa-2021-talk-timeless-timing-attack/ Mon, 18 Apr 2022 14:36:49 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Timing attack that turns infeasible into feasible. Notes https://blog.soreatu.com/posts/xc-code-api-pentesting/ https://blog.soreatu.com/posts/xc-code-api-pentesting/ Fri, 15 Apr 2022 19:51:41 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) 行程卡接口安全测试 Hack for Fun https://blog.soreatu.com/posts/writeup-for-pctf-2022-pressure/ https://blog.soreatu.com/posts/writeup-for-pctf-2022-pressure/ Mon, 11 Apr 2022 13:51:20 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Pressure: a toy private set intersection challenge Writeup https://blog.soreatu.com/posts/notes-on-black-hat-usa-2021-talks-webrtc/ https://blog.soreatu.com/posts/notes-on-black-hat-usa-2021-talks-webrtc/ Sun, 03 Apr 2022 16:22:57 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Several attacks on the state machines of IM softwares Notes https://blog.soreatu.com/posts/writeup-for-lazy-stek-in-line-ctf-2022/ https://blog.soreatu.com/posts/writeup-for-lazy-stek-in-line-ctf-2022/ Sat, 02 Apr 2022 19:33:12 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Lazy STEK: TLS Pre-shared keys + AES-GCM forbidden attack Writeup https://blog.soreatu.com/posts/2021-year-end-summary/ https://blog.soreatu.com/posts/2021-year-end-summary/ Sat, 01 Jan 2022 04:21:11 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) 2021年终总结 Just a Transient Thought https://blog.soreatu.com/posts/a-survey-of-rsa-padding-oracle-attack/ https://blog.soreatu.com/posts/a-survey-of-rsa-padding-oracle-attack/ Wed, 08 Sep 2021 14:00:41 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Notes on several papers relating to RSA Padding Oracle Attack and source code analysis of the lagacy OpenSSL library. Cryptography https://blog.soreatu.com/posts/writeup-for-web-checkin-in-cybrics-ctf-2021/ https://blog.soreatu.com/posts/writeup-for-web-checkin-in-cybrics-ctf-2021/ Sun, 01 Aug 2021 18:19:26 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) We solved the 0-solve hard web challenge <strong>checkin</strong> after CyBRICS CTF 2021 and claimed a reward. Here is our writeup. Writeup https://blog.soreatu.com/posts/writeup-for-bfv-and-psn-in-2021qwb-final/ https://blog.soreatu.com/posts/writeup-for-bfv-and-psn-in-2021qwb-final/ Tue, 13 Jul 2021 10:30:51 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for Writeup for bfv and PSN in 2021qwb Final (2021-07-10 09:00 +30h).<br/> - <strong>bfv</strong>: chosen-ciphertext attack on bfv homomorphic encryption algorithm<br/> - <strong>PSN</strong>: weak key Writeup https://blog.soreatu.com/posts/security-research---cryptographic-protocol/ https://blog.soreatu.com/posts/security-research---cryptographic-protocol/ Sat, 10 Jul 2021 01:37:53 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) a proactive approach to security research on cryptographic protocols https://blog.soreatu.com/posts/collections-of-inspiring-articles/ https://blog.soreatu.com/posts/collections-of-inspiring-articles/ Thu, 13 May 2021 15:27:45 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) some articles that inspire me List https://blog.soreatu.com/posts/mmtls/ https://blog.soreatu.com/posts/mmtls/ Fri, 07 May 2021 00:49:35 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) 微信mmtls协议 Protocol https://blog.soreatu.com/posts/notes-on-economics/ https://blog.soreatu.com/posts/notes-on-economics/ Tue, 04 May 2021 02:51:02 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) 曼昆《经济学原理》 读书笔记 Notes https://blog.soreatu.com/posts/analyasis-of-shadowsocks-and-related-attack/ https://blog.soreatu.com/posts/analyasis-of-shadowsocks-and-related-attack/ Sun, 24 Jan 2021 14:22:24 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) <a href="https://shadowsocks.org/" target="_blank" rel="noreferrer noopener">Shadowsocks</a> is a famous software used for circumventing the GFW. Recently, some security issues of Shadowsocks were exposed, due to the lack of security awareness of the developers when they use some cryptographic components. <br/> This post begins with the analysis of the source code, based on which a practice of packet capturing is conducted. Finally, a security analysis of the vulnerability, as well as a reproduction is given,. Cryptography https://blog.soreatu.com/posts/writeup-for-billboard-and-personal-proxy-in-real-world-ctf-2020-2021/ https://blog.soreatu.com/posts/writeup-for-billboard-and-personal-proxy-in-real-world-ctf-2020-2021/ Wed, 13 Jan 2021 20:19:42 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Solved 2 interesting challenegs in <strong>Real World CTF 2020/2021</strong> (2021-01-09 10:00 +48h). And here is my writeup. Writeup https://blog.soreatu.com/posts/life-is-once-seize-the-day/ https://blog.soreatu.com/posts/life-is-once-seize-the-day/ Mon, 09 Nov 2020 15:44:46 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Some places where I went around, and some pictures that record these journeys. Travel https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-xnuca2020/ https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-xnuca2020/ Mon, 02 Nov 2020 00:39:40 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for 3 crypto challenges in <strong>2020 X-NUCA</strong> (2020-10-30 09:30 +36h). Writeup https://blog.soreatu.com/posts/ops-miscellanea/ https://blog.soreatu.com/posts/ops-miscellanea/ Thu, 22 Oct 2020 22:02:57 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Ops miscellanea Others https://blog.soreatu.com/posts/case-study-coppersmith-related-attack-an-academical-approach/ https://blog.soreatu.com/posts/case-study-coppersmith-related-attack-an-academical-approach/ Tue, 15 Sep 2020 17:36:17 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Timeline of some coppersmith-related-attack research. Cryptography https://blog.soreatu.com/posts/pwn-learning/ https://blog.soreatu.com/posts/pwn-learning/ Tue, 08 Sep 2020 00:55:57 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Some notes on my pwn learning. Bin https://blog.soreatu.com/posts/timeline-lifelong-learning/ https://blog.soreatu.com/posts/timeline-lifelong-learning/ Sun, 06 Sep 2020 13:22:23 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) A list of some books that I have read. List https://blog.soreatu.com/posts/case-study-differetial-cryptanalysis-attack/ https://blog.soreatu.com/posts/case-study-differetial-cryptanalysis-attack/ Fri, 04 Sep 2020 00:14:47 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Differetial Cryptanalysis attack against <strong>6-round DES</strong> and <strong>SM4</strong>. Cryptography https://blog.soreatu.com/posts/intended-solution-to-crypto-problems-in-wmctf-2020/ https://blog.soreatu.com/posts/intended-solution-to-crypto-problems-in-wmctf-2020/ Tue, 11 Aug 2020 20:10:02 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Intended solution to <em>Sum</em>, <em>babySum</em>, and <em>Game</em> in WMCTF 2020. Writeup https://blog.soreatu.com/posts/crypto-research-subset-sum-problem/ https://blog.soreatu.com/posts/crypto-research-subset-sum-problem/ Wed, 01 Jul 2020 10:41:09 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Our work for “天融信杯”第五届（2020年）全国高校密码数学挑战赛 Cryptography https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-5spacectf-2020/ https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-5spacectf-2020/ Thu, 25 Jun 2020 01:27:23 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for 3 crypto challenges in <strong>“第五空间” 智能安全大赛</strong> 2020 (2020-06-24 09:00 +12h).<br/> - (easy) rosb: RSA common modulus attack<br/> - (medium) UnSafeAES: AES-GCM nonce reuse &amp;&amp; forbidden attack<br/> - (interesting) tinysocks: redirect attack on Shadowsocks stream ciphers. Writeup https://blog.soreatu.com/posts/some-thoughts-about-the-past-the-present-and-the-future-2020-06-07/ https://blog.soreatu.com/posts/some-thoughts-about-the-past-the-present-and-the-future-2020-06-07/ Sun, 07 Jun 2020 05:55:58 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) A plain record of the first half year of 2020, some feelings about the first internship, and a dazed plan. Just a Transient Thought https://blog.soreatu.com/posts/upgrade-sagemath-to-version9-on-macos/ https://blog.soreatu.com/posts/upgrade-sagemath-to-version9-on-macos/ Fri, 05 Jun 2020 13:44:59 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Upgrade SageMath and solve several problems occurred during upgrading. Language https://blog.soreatu.com/posts/why-ethereum-has-three-trees/ https://blog.soreatu.com/posts/why-ethereum-has-three-trees/ Wed, 06 May 2020 20:22:09 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) 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. Blockchain https://blog.soreatu.com/posts/writeup-for-de1ctf2020-by-x1ct34m/ https://blog.soreatu.com/posts/writeup-for-de1ctf2020-by-x1ct34m/ Tue, 05 May 2020 00:04:19 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for several problems in De1CTF 2020 by X1cT34m. Writeup https://blog.soreatu.com/posts/ethereum-source-code-reading/ https://blog.soreatu.com/posts/ethereum-source-code-reading/ Mon, 20 Apr 2020 22:01:41 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) 从读以太坊源码来学习区块链技术 Blockchain https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-hufuctf-2020/ https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-hufuctf-2020/ Sun, 19 Apr 2020 20:46:34 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for 3 crypto challenges in <strong>虎符CTF 2020</strong> (2020-04-19 09:00 +8h).<br/> - (easy) <strong>GM</strong>: recover every bit of RSA message by using legendre symbol<br/> - (medium) <strong>mceliece</strong>: break a Mceliece cryptosystem with small parameters<br/> - (easy) <strong>pell</strong>: solve specified pell equations. Writeup https://blog.soreatu.com/posts/blockchain-resource-collections/ https://blog.soreatu.com/posts/blockchain-resource-collections/ Wed, 15 Apr 2020 14:20:36 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) 区块链入门资料总结 Blockchain https://blog.soreatu.com/posts/a-tour-of-go/ https://blog.soreatu.com/posts/a-tour-of-go/ Wed, 15 Apr 2020 01:03:39 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) How I pick up Golang in just one day. Language https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-volgactf-2020/ https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-volgactf-2020/ Sun, 29 Mar 2020 17:36:19 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for 3 easy crypto challenges of VolgaCTF 2020. Writeup https://blog.soreatu.com/posts/case-study-trivial-attack-and-nontrivial-attacks-against-dss/ https://blog.soreatu.com/posts/case-study-trivial-attack-and-nontrivial-attacks-against-dss/ Mon, 16 Mar 2020 21:40:13 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) In this post, we give a concise study of several attaks against <strong>DSS</strong>, including, reused $k$, $k$ generated via LCG, and lattice attack against short $k$. Cryptography https://blog.soreatu.com/posts/cca-on-rsaes-oaep/ https://blog.soreatu.com/posts/cca-on-rsaes-oaep/ Sat, 14 Mar 2020 21:40:13 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Reproduction of James Manger&rsquo;s chosen ciphertext attack on RSAES-OAEP under decryption oracle. Cryptography https://blog.soreatu.com/posts/two-easy-ways-to-factor-rsa/ https://blog.soreatu.com/posts/two-easy-ways-to-factor-rsa/ Sat, 14 Mar 2020 13:53:41 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) In this post, we give some underlying about two easy factorization methods under some specified circumstances. Cryptography https://blog.soreatu.com/posts/writeup-for-gxzyctf-by-x1ct34m/ https://blog.soreatu.com/posts/writeup-for-gxzyctf-by-x1ct34m/ Tue, 10 Mar 2020 22:35:27 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup, by X1cT34m, for several problems in <strong>2020 高校战“疫”网络安全分享赛</strong> (2020-03-07 09:00 +48h).<br/> Writeup https://blog.soreatu.com/posts/intended-solution-to-nhp-in-gxzyctf-2020/ https://blog.soreatu.com/posts/intended-solution-to-nhp-in-gxzyctf-2020/ Tue, 10 Mar 2020 17:23:20 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Leaked length information on the nonce $k$ could be exploited to break DSA. Writeup https://blog.soreatu.com/posts/intended-solution-to-crypto-problems-in-vn-open-competition/ https://blog.soreatu.com/posts/intended-solution-to-crypto-problems-in-vn-open-competition/ Mon, 02 Mar 2020 20:02:13 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) VN公开赛前三道Crypto题的出题思路 Writeup https://blog.soreatu.com/posts/intended-solution-to-ggh-in-gyctf-2020/ https://blog.soreatu.com/posts/intended-solution-to-ggh-in-gyctf-2020/ Tue, 25 Feb 2020 20:14:26 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Break a 150-D GGH cryptosystem using Nguyen&rsquo;s Attack by reducing the problem to a special CVP which is much easier than the general problem. Writeup https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-hgame-2020/ https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-hgame-2020/ Fri, 14 Feb 2020 21:40:13 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Brief writeup for all the crypto challenges in hgame 2020. Writeup https://blog.soreatu.com/posts/an-introduction-to-ntruencrypt-through-a-ctf-challenge/ https://blog.soreatu.com/posts/an-introduction-to-ntruencrypt-through-a-ctf-challenge/ Thu, 06 Feb 2020 09:14:39 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) A gentle introduction to lattice cryptography by solving a 2-D NTRUEncrypt CTF challenge. Cryptography https://blog.soreatu.com/posts/notes-on-an-introduction-to-mathematical-cryptography/ https://blog.soreatu.com/posts/notes-on-an-introduction-to-mathematical-cryptography/ Tue, 10 Dec 2019 23:09:01 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) &quot;An Introduction to Mathematical Cryptography&quot; 读书笔记 （没写完，有空再更新） Notes https://blog.soreatu.com/posts/intended-solution-to-crypto-problems-in-nctf-2019/ https://blog.soreatu.com/posts/intended-solution-to-crypto-problems-in-nctf-2019/ Sat, 30 Nov 2019 21:01:02 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) 19年南邮校赛NCTF所有Crypto题的预期解 Writeup https://blog.soreatu.com/posts/writeup-for-jinengdasai-final-2019/ https://blog.soreatu.com/posts/writeup-for-jinengdasai-final-2019/ Thu, 28 Nov 2019 22:42:23 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for several problems in 2019 中国技能大赛——全国网络安全管理职业技能竞赛 初赛+决赛 Writeup https://blog.soreatu.com/posts/writeup-for-redhat-ctf-2019-by-x1ct34m/ https://blog.soreatu.com/posts/writeup-for-redhat-ctf-2019-by-x1ct34m/ Fri, 15 Nov 2019 09:24:34 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for 2019红帽杯 by X1cT34m Writeup https://blog.soreatu.com/posts/case-study-cryptanalysis-of-vigenere-ciper/ https://blog.soreatu.com/posts/case-study-cryptanalysis-of-vigenere-ciper/ Mon, 28 Oct 2019 13:39:45 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Cryptanalysis of Vigenere Cipher: From theory to practice. Cryptography https://blog.soreatu.com/posts/how-to-start-to-learn-cryptography/ https://blog.soreatu.com/posts/how-to-start-to-learn-cryptography/ Tue, 08 Oct 2019 14:29:43 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Why learn Cryptography, what is Cryptography, and, most importantly, how to learn Cryptography? Cryptography https://blog.soreatu.com/posts/how-to-solve-quadratic-congruences-with-prime-moduli/ https://blog.soreatu.com/posts/how-to-solve-quadratic-congruences-with-prime-moduli/ Tue, 08 Oct 2019 13:12:00 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Summary of two cases to extract square root modulo primes. Cryptography https://blog.soreatu.com/posts/using-python-to-modify-pictures-path-in-markdown-files/ https://blog.soreatu.com/posts/using-python-to-modify-pictures-path-in-markdown-files/ Mon, 07 Oct 2019 13:48:23 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Download all the pictures from <code>imgur</code> and update the path in Markdown files by Python. Language https://blog.soreatu.com/posts/how-to-setup-for-interactive-crypto-problems/ https://blog.soreatu.com/posts/how-to-setup-for-interactive-crypto-problems/ Mon, 23 Sep 2019 16:06:19 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) How to setup the environment of CTF crypto problems that run on the server? This post describes two methods: socat &amp; docker Cryptography https://blog.soreatu.com/posts/case-study-prng/ https://blog.soreatu.com/posts/case-study-prng/ Sun, 22 Sep 2019 13:25:46 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) A brief study of two PRNGs: LCG and MT19937 Cryptography https://blog.soreatu.com/posts/writeup-for-many-problems-in-cnss-recruit-2019/ https://blog.soreatu.com/posts/writeup-for-many-problems-in-cnss-recruit-2019/ Sun, 01 Sep 2019 19:51:24 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for pwn, web, crypto, misc problems in CNSS Recruit 2019 Writeup https://blog.soreatu.com/posts/writeup-for-share-in-cnss-summer-camp-2019/ https://blog.soreatu.com/posts/writeup-for-share-in-cnss-summer-camp-2019/ Sun, 25 Aug 2019 22:51:04 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) CNSS暑假招新赛的一道Crypto题目的writeup Writeup https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-suctf-2019/ https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-suctf-2019/ Tue, 20 Aug 2019 23:56:18 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for 4 crypto challenges in <strong>SUCTF 2019</strong> (2019-08-17 09:00 +36h).<br/> - (easy) <strong>DSA</strong>: exploit the reused ephemeral key <em>k</em> to break DSA<br/> - (easy) <strong>Prime</strong>: factor n into 4 primes<br> - (easy) <strong>MT</strong>: reverse a modified MT algorithm<br/> - (easy) <strong>RSA</strong>: crack a RSA parity oracle<br/> Writeup https://blog.soreatu.com/posts/summary-for-freshman-year/ https://blog.soreatu.com/posts/summary-for-freshman-year/ Mon, 19 Aug 2019 18:43:34 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) A plain record of the freshman year, and some plans. Just a Transient Thought https://blog.soreatu.com/posts/notes-on-a-friendly-introduction-to-number-theory/ https://blog.soreatu.com/posts/notes-on-a-friendly-introduction-to-number-theory/ Fri, 16 Aug 2019 22:58:58 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) &quot;A Friendly Introduction to Number Theory&quot; 读书笔记 Notes https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-de1ctf-2019/ https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-de1ctf-2019/ Tue, 06 Aug 2019 23:46:50 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for 3 crypto challenges in <strong>De1CTF 2019</strong> (2019-08-03 09:00 +48h).<br/> - (easy) <strong>xorz</strong>: recover key from stream cipher<br/> - (medium) <strong>Babylfsr</strong>: reverse a lfsr given (nearly) 2n outputs<br/> - (medium) <strong>Baby RSA</strong>: crack a nesting RSA Writeup https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-cybrics-ctf-2019/ https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-cybrics-ctf-2019/ Mon, 22 Jul 2019 23:37:30 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for 2 crypto challenges in <strong>CyBRICS CTF 2019</strong> (2019-07-20 18:00 +24h).<br/> - (easy) <strong>Zakukozh</strong>: decipher an img file encrypted by Affine Cipher<br/> - (medium) <strong>Fast Crypto</strong>: optimize a brute-force algorithm using mathematical theories Writeup https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-sctf-2019/ https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-sctf-2019/ Mon, 24 Jun 2019 18:03:32 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for 2 crypto challenges in <strong>SCTF 2019</strong> (2019-06-22 09:00 +36h).<br/> - (medium) <strong>warmup</strong>: forge AES message to get verified<br/> - (medium) <strong>babygame</strong>: RSA Broadcast Attack with Linear Padding &amp; forge Writeup https://blog.soreatu.com/posts/writeup-for-easyrsa-in-shendunbei-2019/ https://blog.soreatu.com/posts/writeup-for-easyrsa-in-shendunbei-2019/ Sat, 15 Jun 2019 17:57:07 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for Babyrsa in <strong>2019神盾杯</strong> (2019-06-14 09:00 +24h).<br/> - (medium) <strong>easyRSA</strong>: tackle RSA using 3 attacks Writeup https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-xhlj-final-2019/ https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-xhlj-final-2019/ Fri, 31 May 2019 17:49:51 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for 2 crypto challenges in <strong>2019西湖论剑决赛</strong> (2019-05-30 09:00 +9h).<br/> - (easy) <strong>RSA</strong>: find p+q given n, e, d<br/> - (easy) <strong>VVVV</strong>: Vigenere Cipher Writeup https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-qwb-2019/ https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-qwb-2019/ Wed, 29 May 2019 17:42:27 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for 2 crypto challenges in <strong>qwb 2019</strong> (2019-05-25 09:00 +36h).<br/> - (hard) <strong>copperstudy</strong>: tackle 6 RSA challenges concerning Coppersmith method<br/> - (easy) <strong>强网先锋-辅助</strong>: recover p from two different n1, n2 generated by the same p Writeup https://blog.soreatu.com/posts/reproduction-report-cve-2018-2844/ https://blog.soreatu.com/posts/reproduction-report-cve-2018-2844/ Tue, 28 May 2019 23:12:06 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) A reproduction report on CVE-2018-2844 which enables virtualbox VM to escape from guest to host. Bin https://blog.soreatu.com/posts/writeup-for-babyrsa-in-guetctf-2019/ https://blog.soreatu.com/posts/writeup-for-babyrsa-in-guetctf-2019/ Sat, 25 May 2019 17:38:21 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for Babyrsa in <strong>GUETCTF 2019</strong> (2019-05-22 09:00 +36h).<br/> - (easy) <strong>baby_rsa</strong>: calculate n according to given relationship of p and q Writeup https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-ciscn-2019/ https://blog.soreatu.com/posts/writeup-for-crypto-problems-in-ciscn-2019/ Thu, 25 Apr 2019 16:40:39 +0800 [CC BY-NC-SA 4.0](https://creativecommons.org/licenses/by-nc-sa/4.0/deed.en) Writeup for all the crypto challenges in <strong>CISCN Pre-qualification 2019</strong> (2019-04-20 09:00 +36h).<br/> - (easy) <strong>puzzles</strong>: solve easy math and physics problems<br/> - (easy) <strong>part_des</strong>: decrypt DES with round n encoding result<br/> - (easy) <strong>warmup</strong>: exploit the repeated AES-CRT counter to find the message<br/> - (easy) <strong>Asymmetric</strong>: crack a modified RSA encryption by extracting n Writeup