2f:T439,If used as a replacement for the ***Special Characters*** in the ***tests*** array, this new Regular Expression would support a scenario where passwords can include any emoji in the ***emojis*** array (😅😁🙂😐😟😨) and increase the pool size by 6; the number of possible emojis that would be tested against.

See the following links for emoji keyboard support on Windows and Mac platforms:

[Windows keyboard tips and tricks](https://support.microsoft.com/en-us/windows/windows-keyboard-tips-and-tricks-588e0b72-0fff-6d3f-aeee-6e5116097942)
[Use emoji and symbols on Mac](https://support.apple.com/guide/mac-help/use-emoji-and-symbols-on-mac-mchlp1560/mac)

***regExpToTestforSpecificEmojis*** can now be used as a [test](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/test). Selecting all but the ***thinking face*** emoji (🤔) from the [Radio](https://observablehq.com/@observablehq/input-radio) below will result in a successful test scenario:30:[] 2d:{"title":"Password Entropy Calculator","cells":[{"id":0,"value":"# Password Entropy Calculator\nOr How I Learned to Stop Worrying and Love the [Regular Expression](https://en.wikipedia.org/wiki/Regular_expression)\n\n\n\n**Related:** [Entropy — The Pillar of both Thermodynamics and Information Theory](https://towardsdatascience.com/entropy-the-pillar-of-both-thermodynamics-and-information-theory-138d6e4872fa) \n","pinned":false,"hidden":false,"mode":"md"},{"id":733,"value":" ${tex.block`E=L*\\log_{2}\\left( ℝ\\right)`}\n","pinned":false,"hidden":false,"mode":"md"},{"id":736,"value":"Inputs.bind(\n Inputs.text({\n label: md`**Calculate Entropy for:**`,\n value: \"P@$$W0rd\"\n }),\n viewof password\n)","pinned":false,"hidden":false,"mode":"ojs"},{"id":739,"value":"Entropy\n ? md`**Password's Entropy:** ${Entropy.entropy} ${\n Entropy.emoji\n } ${Entropy.legend.cloneNode(true)}`\n : md``","pinned":false,"hidden":false,"mode":"ojs"},{"id":13,"value":"toc(\"h2,h3,h4\")","pinned":false,"hidden":false,"mode":"ojs"},{"id":10,"value":"## Introduction\n
\nThe [Omni Calculator](https://www.omnicalculator.com/) site hosts thousands of calculators; one of which is a [Password Entropy Calculator](https://www.omnicalculator.com/other/password-entropy). \n\nThis notebook builds on the calculator's work and provides real-time, reactive illustration of the algorithm utilizing [Regular Expressions](https://en.wikipedia.org/wiki/Regular_expression).","pinned":false,"hidden":false,"mode":"md"},{"id":383,"value":"## Algorithm\n
\nAlong with a good explanation of the importance of a high-entropy passwords, the Omni Calculator details a basic algorithm for calculating a password's [Entropy (${tex`E`})](https://en.wikipedia.org/wiki/Entropy_(information_theory%29); a concept [Claude Shannon](https://en.wikipedia.org/wiki/Claude_Shannon) introduced in [Information Theory](https://en.wikipedia.org/wiki/Information_theory):\n\n ${tex.block`E=L*\\log_{2}\\left( ℝ\\right)`}\n\n Where:\n\n* ${tex`L`} is the [password length](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/length); the number of characters in the password.\n* ℝ is the size of the pool of unique characters from which the password is built.\n* ${tex`log_{2}\\left( ℝ\\right)`} is the [base 2 logarithm](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/log2) of ℝ. ","pinned":false,"hidden":false,"mode":"md"},{"id":34,"value":"To calculate the size of the pool of unique characters, ℝ, the calculator determines which of the following characters pools are represented in the password: ","pinned":false,"hidden":false,"mode":"md"},{"id":38,"value":"| Pool | Elements | Pool Size | RegEx | [RegEx Notes](https://www.section.io/engineering-education/password-strength-checker-javascript/) |\n| ------ | -------- |---------- | ----------- | ------- |\n| Digits |\t0-9 | 10 | (?=.*[0-9]) | 0-9 Inclusive |\n| Lower case
Latin letters | a-z |26 | (?=.*[a-z]) | a-z Inclusive |\n| Upper case
Latin letters | A-Z |26 | (?=.*[A-Z]) | A-Z Inclusive |\n| Special Characters
(typical U.S. keyboard)| `~!@#$%^&*()-=_+[{]}\\ |32 | (?=.*[^A-Za-z0-9]) | Not 0-9,a-z or A-Z|\n\nThe **RegEx** column represents the Regular Expression that will be used to [test](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/test) a password's use of a character from a given pool.\n\nA password may have multiple characters from any given pool, but the pool size contribution of one or more characters in any given pool is only accumulated once into the the value of ℝ.","pinned":false,"hidden":false,"mode":"md"},{"id":50,"value":"For future flexibility, the following cell hosts an array of Regular Expressions with respective pool size contribution values as detailed in the table above:","pinned":false,"hidden":false,"mode":"md"},{"id":398,"value":"// [[RegExp,poolsize]]\ntests = [\n [/(?=.*[a-z])/, 26], // Lowercase letters\n [/(?=.*[A-Z])/, 26], // Uppercase letters\n [/(?=.*[0-9])/, 10], // Digits\n [/(?=.*[^A-Za-z0-9])/, 32] // Special characters\n]","pinned":true,"hidden":false,"mode":"ojs"},{"id":428,"value":"With ***tests*** established, the following function will [test](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/test) a password against each Regular Expression and accumulate the total pool size (ℝ) by invoking a [reduce](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce) operation against the array . \n\nThe function takes advantage of the JavaScript behavior for a [***false*** boolean's coercion to 0 in arithmetic expressions](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean):","pinned":false,"hidden":false,"mode":"md"},{"id":403,"value":"ℝ = (password, tests) =>\n tests.reduce((ΣR, rP) => ΣR + rP[0].test(password) * rP[1], 0)","pinned":true,"hidden":false,"mode":"ojs"},{"id":765,"value":"### Alternate tests ","pinned":false,"hidden":false,"mode":"md"},{"id":440,"value":"The calculator can be constructed with alternate Regular Expressions in the ***tests*** array. \n\nTo show this, consider the following array of [emojis](https://unicode.org/emoji/charts/full-emoji-list.html#1f600) that will be used to illustrate/qualify the relative Entropy strengths for a password: ","pinned":false,"hidden":false,"mode":"md"},{"id":444,"value":"// [[Entropy Threshold,emoji]]\nemojis = [\n [130, \"😅\"],\n [60, \"😁\"],\n [30, \"🙂\"],\n [25, \"😐\"],\n [15, \"😟\"],\n [0, \"😨\"]\n]","pinned":true,"hidden":false,"mode":"ojs"},{"id":447,"value":"Let's build a Regular Expression that will [test](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/test) if a string includes any emoji in the ***emojis*** array. \n\nThe Regular Expression is built with [Disjunctions (|) ](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions/Cheatsheet):","pinned":false,"hidden":false,"mode":"md"},{"id":609,"value":"regExpToTestforSpecificEmojis = new RegExp(\n `[` + emojis.map(([, emoji]) => emoji).join(`|`) + `]`\n)","pinned":true,"hidden":false,"mode":"ojs"},{"id":582,"value":"$2f","pinned":false,"hidden":false,"mode":"md"},{"id":577,"value":"viewof selectedEmoji = Inputs.radio(\n emojis.map(([_, emoji]) => emoji).concat(\"🤔\"),\n { label: \"Select emoji to test\", value: emojis[0][1] }\n)","pinned":true,"hidden":false,"mode":"ojs"},{"id":751,"value":"md`${selectedEmoji} is ${\n [`**not**`, ``][+regExpToTestforSpecificEmojis.test(selectedEmoji)]\n} in the ${emojis.map(([_, emoji]) => emoji)} array.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":863,"value":"**Note:** An emoji's [length value is ${selectedEmoji.length} code units](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/length):","pinned":false,"hidden":false,"mode":"md"},{"id":812,"value":"selectedEmoji.length","pinned":true,"hidden":false,"mode":"ojs"},{"id":58,"value":"## Entropy Calculator\n
\nWith a function for ℝ established, the Entropy of a password can then be calculated. \n\nType in various candidate passwords below to see their respective Entropy calculation:","pinned":false,"hidden":false,"mode":"md"},{"id":114,"value":"### Password","pinned":false,"hidden":false,"mode":"md"},{"id":61,"value":"viewof password = Inputs.text({\n label: md`**Calculate Entropy for:**`,\n value: \"P@$$W0rd\"\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":289,"value":"calcEntropy = Entropy\n ? md`**Password's Entropy:** ${Entropy.entropy} ${Entropy.emoji} ${Entropy.legend}`\n : md``","pinned":false,"hidden":false,"mode":"ojs"},{"id":373,"value":"### Step-By-Step Calculation","pinned":false,"hidden":false,"mode":"md"},{"id":118,"value":"#### L (Password Length)","pinned":false,"hidden":false,"mode":"md"},{"id":91,"value":"Entropy\n ? md`${tex.block`L='\\verb|${password}|'.length`}\n${tex.block`L=${Entropy.L}`}`\n : md``","pinned":false,"hidden":false,"mode":"ojs"},{"id":120,"value":"#### ℝ (Pool Size)","pinned":false,"hidden":false,"mode":"md"},{"id":64,"value":"Entropy\n ? md`| Pool | Elements |
Pool Size
Contributions (Rn) | \n| ------ | ------ | -------- |\n| Digits |\t0-9 |\t${/(?=.*[0-9])/.test(password) * 10} | \n| Lower case
Latin letters |\ta-z | ${/(?=.*[a-z])/.test(password) * 26} |\n| Upper case
Latin letters |\tA-Z | ${/(?=.*[A-Z])/.test(password) * 26} |\n| Special Characters
(typical U.S. keyboard) | \\`~!@#$%^&*()-=_+[{]}\\ | ${\n /(?=.*[^A-Za-z0-9])/.test(password) * 32\n } |\n| | | ${tex`ℝ = {\\sum}ℝn =`} **${Entropy.R}**|`\n : md``","pinned":false,"hidden":false,"mode":"ojs"},{"id":123,"value":"#### Entropy\n${Entropy ? Entropy.legend.cloneNode(true) : md``}","pinned":false,"hidden":false,"mode":"md"},{"id":93,"value":"{\n if (password.length == 0) return md``;\n\n return md` \n${tex.block`E=L*\\log_{2}\\left( ℝ\\right)`}\n${tex.block`E=${Entropy.L}*\\log_{2}\\left( ${Entropy.R}\\right)`}\n${tex.block`E=${Entropy.L}*\\left( ${Math.log2(Entropy.R)}\\right)`}\n${tex.block`E=${Entropy.entropy} ${Entropy.emoji} `} `;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":250,"value":"## ⚠️ Caution \nPassword Entropy is only one consideration for a strong password:\n

**How do I create a strong password?**\n\n1. Make sure your password cannot be found in any **dictionary of leaked passwords**. Make it as unique as possible.\n2. **Increase the length** of the password.\n3. **Enlarge the pool** of symbols from which you take characters. Use lower case letters, upper case letters, digits, and special symbols.\n\n**When is a password secure?**\n\nA password is secure if it has **at least 50 bits of entropy* and does not appear in any *list of leaked passwords**.\n\n**How many bits of entropy for a good password?**\n\nFor **non-vital accounts, 25-30 bits** of entropy are enough. For more important accounts, **aim for 60-80 bits of entropy**, up to 100 for crucial ones.\n

\n--[Password Entropy Calculator](https://www.omnicalculator.com/other/password-entropy)","pinned":false,"hidden":false,"mode":"md"},{"id":286,"value":"## Objects Used in the Notebook","pinned":false,"hidden":false,"mode":"md"},{"id":267,"value":"/* Adopted from: \nhttps://www.omnicalculator.com/other/password-entropy#how-to-use-this-password-entropy-calculator\nhttps://developer.mozilla.org/en-US/docs/web/javascript/reference/global_objects/regexp/test\nhttps://www.section.io/engineering-education/password-strength-checker-javascript/ \n*/\nfunction getEntropy(password) {\n if (password.length == 0) return undefined;\n\n const L = password.length;\n\n const R = ℝ(password, tests);\n\n const entropy = Math.floor(password.length * Math.log2(R) * 100) / 100;\n const emoji = emojis.find((d) => Math.round(entropy) > d[0])[1];\n\n const legend = Legend(\n d3.scaleOrdinal(\n [\"<15\", \"15-24\", \"25-29\", \"30-59\", \"60-129\", \"≥130\"],\n d3.schemeRdYlGn[6]\n ),\n {\n //title: \"Entropy\",\n tickSize: 0\n }\n );\n\n return { L, R, entropy, emoji, legend };\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":272,"value":"Entropy = getEntropy(password)","pinned":false,"hidden":false,"mode":"ojs"},{"id":5,"value":"import { toc } from \"@nebrius/indented-toc\"","pinned":false,"hidden":false,"mode":"ojs"},{"id":292,"value":"import { Legend, Swatches } from \"@d3/color-legend\"","pinned":false,"hidden":false,"mode":"ojs"}],"files":"$W30","stdlib":"1","titling":"auto"}