问题描述
几个月前，我的任务是为我们的 Web 应用程序实现一个独特的随机代码.代码必须对用户友好且尽可能小，但本质上仍然是随机的(因此用户无法轻易预测序列中的下一个代码).
A few months back I was tasked with implementing a unique and random code for our web application. The code would have to be user friendly and as small as possible, but still be essentially random (so users couldn't easily predict the next code in the sequence).
它最终生成了如下所示的值:
It ended up generating values that looked something like this:
Af3nT5Xf2
不幸的是，我从未对实施感到满意.Guid 是不可能的，它们太大了，用户难以输入.我希望有更多的 4 或 5 个字符/数字，但如果我们编码为，我们的特定实现会生成明显的图案序列少于 9 个字符.
Unfortunately, I was never satisfied with the implementation. Guid's were out of the question, they were simply too big and difficult for users to type in. I was hoping for something more along the lines of 4 or 5 characters/digits, but our particular implementation would generate noticeably patterned sequences if we encoded to less than 9 characters.
这是我们最终做的:
我们从数据库中提取了一个唯一的连续 32 位 ID.然后我们将它插入到一个 64 位 RANDOM 整数的中心位中.我们创建了一个易于键入和识别的字符的查找表(A-Z、a-z、2-9 跳过了容易混淆的字符，例如 L、l、1、O、0 等).最后，我们使用该查找表对 64 位整数进行 base-54 编码.高位是随机的，低位是随机的，但中心位是连续的.
We pulled a unique sequential 32bit id from the database. We then inserted it into the center bits of a 64bit RANDOM integer. We created a lookup table of easily typed and recognized characters (A-Z, a-z, 2-9 skipping easily confused characters such as L,l,1,O,0, etc.). Finally, we used that lookup table to base-54 encode the 64-bit integer. The high bits were random, the low bits were random, but the center bits were sequential.
最终的结果是一个比 guid 小得多的代码，而且看起来是随机的，尽管它绝对不是.
The final result was a code that was much smaller than a guid and looked random, even though it absolutely wasn't.
我从未对这种特殊的实现感到满意.你们会怎么做?
I was never satisfied with this particular implementation. What would you guys have done?
推荐答案
我会这样做.
我会获得一个常用英语单词列表以及使用频率和一些语法信息(比如它是名词还是动词?).我认为您可以在 intertubes 周围寻找一些副本.Firefox 是开源的，它有一个拼写检查器......所以它必须以某种方式获得.
I'd obtain a list of common English words with usage frequency and some grammatical information (like is it a noun or a verb?). I think you can look around the intertubes for some copy. Firefox is open-source and it has a spellchecker... so it must be obtainable somehow.
然后我会对其运行过滤器，以便删除晦涩的单词并排除太长的单词.
Then I'd run a filter on it so obscure words are removed and that words which are too long are excluded.
然后我的生成算法将从列表中选择 2 个单词并将它们连接起来并添加一个随机的 3 位数字.
Then my generation algorithm would pick 2 words from the list and concatenate them and add a random 3 digits number.
我还可以在动词/名词之间随机化单词选择模式，例如
I can also randomize word selection pattern between verb/nouns like
eatCake778
pickBasket524
乘坐Flyer113等等.
外壳不必是驼色外壳，您也可以随机化.您还可以随机排列数字和动词/名词的位置.
the case needn't be camel casing, you can randomize that as well. You can also randomize the placement of the number and the verb/noun.
由于这是很多随机性，Jeff 的 天真的危险 是必读.还要确保提前研究好字典攻击.
And since that's a lot of randomizing, Jeff's The Danger of Naïveté is a must-read. Also make sure to study dictionary attacks well in advance.
在我实现它之后，我会运行一个测试以确保我的算法永远不会发生冲突.如果冲突率很高，那么我会使用参数(使用的名词数量，使用的动词数量，随机数的长度，单词总数，不同类型的套管等)
And after I'd implemented it, I'd run a test to make sure that my algorithms should never collide. If the collision rate was high, then I'd play with the parameters (amount of nouns used, amount of verbs used, length of random number, total number of words, different kinds of casings etc.)
这篇关于如何生成唯一、小的、随机且用户友好的密钥?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！