https://blog.haitai-social.com/note/%E7%B3%BB%E7%BB%9F%E7%90%86%E8%AE%BA%E8%AF%BE%E7%A8%8B/%E7%AE%97%E6%B3%95%E5%92%8C%E5%8D%8F%E8%AE%AE%E4%B8%AD%E7%9A%84%E5%AE%89%E5%85%A8%E6%9C%BA%E5%88%B6/4.block-hash-mac/Recent content in 4.Block-Hash-MAC on 蛇索尼 AidenHugo -- gohugo.iozh-CNshesl-meow@qq.com (佘崧林)shesl-meow@qq.com (佘崧林)Wed, 12 Jun 2019 05:06:21 +0800https://blog.haitai-social.com/note/%E7%B3%BB%E7%BB%9F%E7%90%86%E8%AE%BA%E8%AF%BE%E7%A8%8B/%E7%AE%97%E6%B3%95%E5%92%8C%E5%8D%8F%E8%AE%AE%E4%B8%AD%E7%9A%84%E5%AE%89%E5%85%A8%E6%9C%BA%E5%88%B6/4.block-hash-mac/4.1.blockciphers/Wed, 12 Jun 2019 05:06:21 +0800shesl-meow@qq.com (佘崧林)https://blog.haitai-social.com/note/%E7%B3%BB%E7%BB%9F%E7%90%86%E8%AE%BA%E8%AF%BE%E7%A8%8B/%E7%AE%97%E6%B3%95%E5%92%8C%E5%8D%8F%E8%AE%AE%E4%B8%AD%E7%9A%84%E5%AE%89%E5%85%A8%E6%9C%BA%E5%88%B6/4.block-hash-mac/4.1.blockciphers/Overview property: Diffusion: any bits from the input message should affect whole cipher text. Confusion: with different key, the cipher message should be completely different. 块加密可以用以下一个函数表示：$$C = E_k(x) = f(x, k), x,k,C \in \mathbb{F}_2^{(n)}$$ Requirements of f: Nonelinearity: a minimum distance between f and all the linear, affine functions (confusion). Resist linear cryptanalysis.https://blog.haitai-social.com/note/%E7%B3%BB%E7%BB%9F%E7%90%86%E8%AE%BA%E8%AF%BE%E7%A8%8B/%E7%AE%97%E6%B3%95%E5%92%8C%E5%8D%8F%E8%AE%AE%E4%B8%AD%E7%9A%84%E5%AE%89%E5%85%A8%E6%9C%BA%E5%88%B6/4.block-hash-mac/4.2.hashfunctions/Wed, 12 Jun 2019 05:06:21 +0800shesl-meow@qq.com (佘崧林)https://blog.haitai-social.com/note/%E7%B3%BB%E7%BB%9F%E7%90%86%E8%AE%BA%E8%AF%BE%E7%A8%8B/%E7%AE%97%E6%B3%95%E5%92%8C%E5%8D%8F%E8%AE%AE%E4%B8%AD%E7%9A%84%E5%AE%89%E5%85%A8%E6%9C%BA%E5%88%B6/4.block-hash-mac/4.2.hashfunctions/Overview A hash function h(x) is a map from n bits to m bits where m<n An output of a hash function is called a message digest or a hash value. A hash function should satisfy the following property: Collision resistance. Second pre-image resistance. Given x, if the probability to find $$y \not= x $$ such that $$h(y) = h(x)$$ is negligible, then the function h is called second pre-imagehttps://blog.haitai-social.com/note/%E7%B3%BB%E7%BB%9F%E7%90%86%E8%AE%BA%E8%AF%BE%E7%A8%8B/%E7%AE%97%E6%B3%95%E5%92%8C%E5%8D%8F%E8%AE%AE%E4%B8%AD%E7%9A%84%E5%AE%89%E5%85%A8%E6%9C%BA%E5%88%B6/4.block-hash-mac/4.3.mac/Wed, 12 Jun 2019 05:06:21 +0800shesl-meow@qq.com (佘崧林)https://blog.haitai-social.com/note/%E7%B3%BB%E7%BB%9F%E7%90%86%E8%AE%BA%E8%AF%BE%E7%A8%8B/%E7%AE%97%E6%B3%95%E5%92%8C%E5%8D%8F%E8%AE%AE%E4%B8%AD%E7%9A%84%E5%AE%89%E5%85%A8%E6%9C%BA%E5%88%B6/4.block-hash-mac/4.3.mac/Overview MAC is used for providing authenticity of a user or source originality. Method for generating MAC: Pseudo-random sequence generators (or stream cipher). Block ciphers through CBC mode. Keyed hash functions.