2023 看雪 KCTF 98k 战队防守方精准攻击赛题设计

本篇博客是 2023 看雪 CTF 年度赛上精准攻击赛题的官方题解与设计思路，精准攻击赛题属于逆向题 ，但是主要的难点在于密码方向，本题基于两个后量子困难问题（SDP，SSP）设计，解出情况为 0 解，但是由于出题时间较晚，没有拿到最佳坦克奖 orz。最终 98k 战队攻击方排名第一，防守方：坦克奖排名第二，精致奖排名第二。

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Paper summary - Bootstrapping in FHEW-like Cryptosystems

Reference Paper ：Bootstrapping in FHEW-like Cryptosystems . This blog is a summary of the paper which is the main reference for the BinFHE implementation in OpenFHE. The main contribution is to realize the homomorphic standardized variant of TFHE, that is, to expand the private key sampling range of TFHE from binary to any sampling range, such as ternary , and compared FHEW and TFHE when the private key sampling range is the same. Evaluate the bootstrapping speed, bootstrapping key size and other parameters of the two.

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Cryptography Topic: Multivariate Quadratic Cryptography

多变量密码学（Multivariate cryptography）是在有限域 上多元多项式上实现的密码学，多用于非对称加密，亦称多变量公钥密码学（Multivariate Public Key Cryptography abbr. MPKC）。通常使用二次多项式（Multivariate Quadratic abbr. MQ ）来保证其非线性，多元多次多项式的求解问题证明是 NP-Complete 的，因此 MPKC 是后量子密码体系内重要的研究方向。该篇博客是 Multivariate Public Key Cryptography 文献中有关 Matsumoto-Imai Cryptosystem 以及其变体的内容研究总结。

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    缺失模块。
    1、请确保node版本大于6.2
    2、在博客根目录（注意不是yilia-plus根目录）执行以下命令：
    npm i hexo-generator-json-content --save

    3、在根目录_config.yml里添加配置： 

      jsonContent:
    meta: false
    pages: false
    posts:
      title: true
      date: true
      path: true
      text: false
      raw: false
      content: false
      slug: false
      updated: false
      comments: false
      link: false
      permalink: false
      excerpt: false
      categories: false
      tags: true


Hi, this is tl2cents
Currently Ph.D at IIE of UCAS
Graduated from USTC (2018-2022)

CTFer
Focus on blockchain, crypto and reversing
Team member of NeSE and Nebula

Research
Blockchain | ETH | FHE
PQC | Cryptography | Android

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