Hashing function (散列函式) 在网页应用中被广泛采用,从数码签署.错误检测.登入验证.到压缩储存空间,由于它的原理比较复杂,很多人把它跟加密函式混淆,对于如何运用hash function,如何选择合适的hash function,和它的优点缺点都不清楚,本文尝试解答这些问题. 算法(algorithm),通常用来把一大串不定长度的数据影射到一个固定长度的.较短的数据,这个固定长度的数据称为hashing value (散列值). 1. 数码签署 当然,我们还要确保hash v…

Which hash algorithom to choose for new application: https://www.owasp.org/index.php/Password_Storage_Cheat_Sheet Argon2[*7] is the winner of the password hashing competition and should be considered as your first choice for new applications; We can…

Hash function From Wikipedia, the free encyclopedia   A hash function that maps names to integers from 0 to 15. There is a collision between keys "John Smith" and "Sandra Dee". A hash function is any function that maps data of arbitrar…

一. 近邻搜索 从这里开始我将会对LSH进行一番长篇大论.因为这只是一篇博文,并不是论文.我觉得一篇好的博文是尽可能让人看懂,它对语言的要求并没有像论文那么严格,因此它可以有更强的表现力. 局部敏感哈希,英文locality-sensetive hashing,常简称为LSH.局部敏感哈希在部分中文文献中也会被称做位置敏感哈希.LSH是一种哈希算法,最早在1998年由Indyk在[1]上提出.不同于我们在数据结构教材中对哈希算法的认识,哈希最开始是为了减少冲突方便快速增删改查,在这里LSH恰恰相…

偶然发现一篇哈希的综述文章,虽然是1996年写的,里面的一些评测在今天看来早已经小case了.但是今天仍然极具参考价值. 地址:http://www.drdobbs.com/database/hashing-rehashed/184409859 正文: Hashing algorithms occupy a unique place in the hearts of programmers. Discovered early on in computer science, they are am…

MySQL :: MySQL 8.0 Reference Manual :: 23 Partitioning https://dev.mysql.com/doc/refman/8.0/en/partitioning.html [仅支持  InnoDB and NDB ] In MySQL 8.0, partitioning support is provided by the InnoDB and NDB storage engines. MySQL 8.0 does not currently…

Motivation The task of finding nearest neighbours is very common. You can think of applications like finding duplicate or similar documents, audio/video search. Although using brute force to check for all possible combinations will give you the exact…

hashlib - Secure hashes and message digests - Python 3.8.3 documentation https://docs.python.org/3.8/library/hashlib.html#randomized-hashing BLAKE2 https://blake2.net/#qa Q: So I shouldn't use BLAKE2 for hashing user passwords?  A: You shouldn't use…

差分进化算法 (Differential Evolution)   Differential Evolution(DE)是由Storn等人于1995年提出的,和其它演化算法一样,DE是一种模拟生物进化的随机模型,通过反复迭代,使得那些适应环境的个体被保存了下来.但相比于进化算法,DE保留了基于种群的全局搜索策略,采用实数编码.基于差分的简单变异操作和一对一的竞争生存策略,降低了遗传操作的复杂性.同时,DE特有的记忆能力使其可以动态跟踪当前的搜索情况,以调整其搜索策略,具有较强的全局收敛能力和鲁棒…

Holding Your Objects In general, your programs will always be creating new objects based on some criteria that will be known only at run time. You can't rely on creating a named reference to hold each one of your objects. The compiler-supported type…