* dice 6 [1-6]
* decimal [0-9]
* hexadecimal [0-9A-F]
+ * card [A2-9TJQK][CDHS]
*
* Automatically uses lowest entropy to avoid issues such as interpretting 0101
* as hexadecimal which would be 16 bits when really it's only 4 bits of binary
while (entropyBin.length < expectedBits) {
entropyBin = "0" + entropyBin;
}
+ // Assume cards are NOT replaced.
+ // Additional entropy decreases as more cards are used. This means
+ // total possible entropy is measured using n!, not base^n.
+ // eg the second last card can be only one of two, not one of fifty two
+ // so the added entropy for that card is only one bit at most
+ if (base.asInt == 52) {
+ // Get the maximum value WITHOUT replacement
+ var totalDecks = Math.ceil(base.parts.length / 52);
+ var totalCards = totalDecks * 52;
+ var totalCombos = factorial(52).pow(totalDecks);
+ var totalRemainingCards = totalCards - base.parts.length;
+ var remainingDecks = Math.floor(totalRemainingCards / 52);
+ var remainingCards = totalRemainingCards % 52;
+ var remainingCombos = factorial(52).pow(remainingDecks).multiply(factorial(remainingCards));
+ var currentCombos = totalCombos.divide(remainingCombos);
+ var numberOfBits = Math.log2(currentCombos);
+ var maxWithoutReplace = BigInteger.pow(2, numberOfBits);
+ // aggresive flooring of numberOfBits by BigInteger.pow means a
+ // more accurate result can be had for small numbers using the
+ // built-in Math.pow function.
+ if (numberOfBits < 32) {
+ maxWithoutReplace = BigInteger(Math.round(Math.pow(2, numberOfBits)));
+ }
+ // Get the maximum value WITH replacement
+ var maxWithReplace = BigInteger.pow(52, base.parts.length);
+ // Calculate the new value by scaling the original value down
+ var withoutReplace = entropyInt.multiply(maxWithoutReplace).divide(maxWithReplace);
+ // Left pad with zeros based on number of bits
+ var entropyBin = withoutReplace.toString(2);
+ var numberOfBitsInt = Math.floor(numberOfBits);
+ while (entropyBin.length < numberOfBitsInt) {
+ entropyBin = "0" + entropyBin;
+ }
+ }
// Supply a 'filtered' entropy string for display purposes
var entropyClean = base.parts.join("");
var entropyHtml = base.parts.join("");
entropyHtml = entropyHtml.replace(/H/g, "<span class='card-suit heart'>\u2665</span>");
entropyHtml = entropyHtml.replace(/S/g, "<span class='card-suit spade'>\u2660</span>");
}
+ // Return the result
var e = {
binaryStr: entropyBin,
cleanStr: entropyClean,
return BigInteger.log(x) / BigInteger.log(2);
};
+ // Depends on BigInteger
+ function factorial(n) {
+ if (n == 0) {
+ return 1;
+ }
+ f = BigInteger.ONE;
+ for (var i=1; i<=n; i++) {
+ f = f.multiply(new BigInteger(i));
+ }
+ return f;
+ }
+
})();
</script>
<script>(function() {
}
function showEntropyFeedback(entropy) {
+ var numberOfBits = entropy.binaryStr.length;
var strength = "extremely weak";
- if (entropy.binaryStr.length >= 64) {
+ if (numberOfBits >= 64) {
strength = "very weak";
}
- if (entropy.binaryStr.length >= 96) {
+ if (numberOfBits >= 96) {
strength = "weak";
}
- if (entropy.binaryStr.length >= 128) {
+ if (numberOfBits >= 128) {
strength = "strong";
}
- if (entropy.binaryStr.length >= 160) {
+ if (numberOfBits >= 160) {
strength = "very strong";
}
- if (entropy.binaryStr.length >= 192) {
+ if (numberOfBits >= 192) {
strength = "extremely strong";
}
// If time to crack is less than one day, and password is considered
console.log("Error detecting entropy strength with zxcvbn:");
console.log(e);
}
- var bitsStr = getNumberOfEntropyBits(entropy);
- var wordCount = Math.floor(entropy.binaryStr.length / 32) * 3;
var entropyTypeStr = getEntropyTypeStr(entropy);
+ var wordCount = Math.floor(numberOfBits / 32) * 3;
+ var bitsPerEvent = Math.log2(entropy.base.asInt).toFixed(2);
+ if (entropy.base.asInt == 52) {
+ bitsPerEvent = bitsPerEvent + " (or less)";
+ }
DOM.entropyFiltered.html(entropy.cleanHtml);
DOM.entropyType.text(entropyTypeStr);
DOM.entropyStrength.text(strength);
DOM.entropyEventCount.text(entropy.base.ints.length);
- DOM.entropyBits.text(bitsStr);
+ DOM.entropyBits.text(numberOfBits);
DOM.entropyWordCount.text(wordCount);
DOM.entropyBinary.text(entropy.binaryStr);
- DOM.entropyBitsPerEvent.text(Math.log2(entropy.base.asInt).toFixed(2));
- }
-
- function getNumberOfEntropyBits(entropy) {
- var bitsStr = entropy.binaryStr.length.toString();
- // If using cards, assume they are not reused, thus additional entropy
- // decreases as more cards are used. This means entropy is measured
- // using n!, not base^n.
- // eg the second last card can be only one of two, not one of fifty two
- // so the added entropy for that card is only one bit at most
- if (entropy.base.asInt == 52) {
- var totalDecks = Math.ceil(entropy.base.parts.length / 52);
- var totalCards = totalDecks * 52;
- var totalCombos = factorial(52).pow(totalDecks);
- var totalRemainingCards = totalCards - entropy.base.parts.length;
- var remainingDecks = Math.floor(totalRemainingCards / 52);
- var remainingCards = totalRemainingCards % 52;
- var remainingCombos = factorial(52).pow(remainingDecks) * factorial(remainingCards);
- var currentCombos = totalCombos.divide(remainingCombos);
- bitsStr = currentCombos.toString(2).length.toString();
- }
- return bitsStr
+ DOM.entropyBitsPerEvent.text(bitsPerEvent);
}
function getEntropyTypeStr(entropy) {
var dupeTracker = {};
for (var i=0; i<entropy.base.parts.length; i++) {
var card = entropy.base.parts[i];
- if (card in dupeTracker) {
+ var cardUpper = card.toUpperCase();
+ if (cardUpper in dupeTracker) {
dupes.push(card);
}
- dupeTracker[card] = true;
+ dupeTracker[cardUpper] = true;
}
if (dupes.length > 0) {
var dupeWord = "duplicates";
if (uniqueCards.length == 52) {
cardDetail.unshift("full deck");
}
+ // Detect missing cards
+ var values = "A23456789TJQK";
+ var suits = "CDHS";
+ var missingCards = [];
+ for (var i=0; i<suits.length; i++) {
+ for (var j=0; j<values.length; j++) {
+ var card = values[j] + suits[i];
+ if (!(card in dupeTracker)) {
+ missingCards.push(card);
+ }
+ }
+ }
+ // Display missing cards if six or less, ie clearly going for full deck
+ if (missingCards.length > 0 && missingCards.length <= 6) {
+ var msg = missingCards.length + " missing: " + missingCards.slice(0,3).join(" ");
+ if (missingCards.length > 3) {
+ msg += "...";
+ }
+ cardDetail.push(msg);
+ }
// Add card details to typeStr
if (cardDetail.length > 0) {
typeStr += " (" + cardDetail.join(", ") + ")";
return typeStr;
}
- // Depends on BigInteger
- function factorial(n) {
- if (n == 0) {
- return 1;
- }
- f = BigInteger.ONE;
- for (var i=1; i<=n; i++) {
- f = f.multiply(new BigInteger(i));
- }
- return f;
- }
-
var networks = [
{
name: "Bitcoin",
projects / perso / Immae / Projets / Cryptomonnaies / BIP39.git / commitdiff
