The Diceware Passphrase Home Page

This page offers a better way to create a strong, yet easy to remember, passphrase for use with encryption and security programs. Weak passwords and passphrases are one of the most common flaws in computer security. Take a few minutes and learn how to do it right. The information presented here can be used by anyone. No background in cryptography or mathematics is required. Just follow the simple steps below. If you'd like to know even more about passphrases, see the Frequently Asked Questions (FAQ) , and please checkout the Diceware Security Blog, for commentary on the latest developments in computer security and shared secret authentication.

This page is also available in Chinese, Esperanto, Finnish, French, Italian, Japanese, Polish and Spanish. There are also Diceware word lists available in Basque, Bulgarian, Catalan, Chinese, Czech, Danish, Dutch, Esperanto, Estonian, Finnish, French, German, Hebrew, Hungarian, Italian, Japanese, Latin, Maori, Norwegian, Polish, Portuguese, Romanian, Russian, Slovak, Slovenian, Spanish, Swedish and Turkish, 28 languages besides English, all kindly contributed by our users.

Try our free Big Number Calculator Java applet. It lets you perform many of the calculations used in public key cryptography. It should work on most modern browsers on computers that support Java (that does not include Apple's iOS, sorry).







What Is A Passphrase?

A passphrase is a bunch of words and characters that you type in to your computer to let it know for sure that the person typing is you. Most security programs allow you to enter a passphrase instead of just a short password for added protection against attackers. Some programs also use your passphrase to form a cryptographic key to encrypt your data.



Passphrases are used with Wi-Fi wireless network security systems such as WPA and WPA2, when used in personal shared key (PSK) mode. The security of both systems depends on the strength of the passphrase you chose.

Phil Zimmermann's popular encryption program PGP requires you to make up a passphrase that you enter whenever you sign or decrypt messages. So does the open-source version, GnuPG.

Popular password manager programs require a master password or passphrase to protect the data they store.

Passphrases are used with disk encryption programs such as PGPdisk and Apple's FileVault. Many organizations require disk encryption on laptops to meet regulatory requirements for protecting sensitive information.

The latest versions of most popular operating systems, including Windows 10, MacOS and iOS, let you use longer passphrases for log-on identification.

Digital currencies, such as BitCoin, use passphrases to protect the “coins” from misappropriation. Using a short passphrase as an answer to a required "security question" (like "What city were you born in?") protects you against attempts to discover your answer by researching your online data.

You should follow the Diceware™ instructions here to create your passphrase before installing a WiFi router, creating your PGP or GPG key, opening a new security account or setting up an encrypted disk or digital currency wallet, so when you are asked to enter your new password, you'll be ready.

Passphrases differ from passwords only in length. Passwords are usually short, six to ten characters. Short passwords are mostly OK for logging onto computer system that are programmed to detect multiple incorrect guesses and to protect the stored passwords properly, but they are not safe for use with encryption systems. Passphrases are usually much longer -- typically 25 to 64 characters (including spaces). Their greater length makes passphrases more secure. Modern passphrases were invented by Sigmund N. Porter in 1981. If all you need right now is a login password, click here. Otherwise, read on.

Picking a good passphrase is one of the most important things you can do to preserve the privacy of your computer data and e-mail messages. A passphrase should be:



Known only to you

Long enough to be secure

Hard to guess – even by someone who knows you well

Easy for you to remember Easy for you to type accurately

What Is Diceware?

Diceware™ is a method for picking passphrases that uses ordinary dice to select words at random from a special list called the Diceware Word List. Each word in the list is preceded by a five digit number. All the digits are between one and six, allowing you to use the outcomes of five dice rolls to select a word from the list.

Here is a short excerpt from the English Diceware word list:

16655 clause 16656 claw 16661 clay 16662 clean 16663 clear 16664 cleat 16665 cleft 16666 clerk 21111 cliche 21112 click 21113 cliff 21114 climb 21115 clime 21116 cling 21121 clink 21122 clint 21123 clio 21124 clip 21125 clive 21126 cloak 21131 clock

The complete list contains 7776 short words, abbreviations and easy-to-remember character strings. The average length of each word is about 4.2 characters. The biggest words are six characters long. The English list is based on a longer word list posted to the Internet news group sci.crypt by Peter Kwangjun Suk. An alternative list, edited by Alan Beale, contains fewer Americanisms and obscure words. And there are lists for many other languages. You can also download the Diceware word list in PDF format or in PostScript format.

Using Diceware

To use the Diceware list you will need one or more dice. Dice come with many board games and are sold separately at toy, hobby, and magic stores, as well as online. Braille dice are also available. You can purchase a set of five casino-grade dice online from Amazon.com or Ebay.com for about $16, but they are overkill for this purpose. Do not use a computer program or electronic dice generator.

Download the complete Diceware list, the alternative Beale list or a list in the language of your choice, and save it on your computer. Print it out if you like. Then return to this page. Decide how many words you want in your passphrase. A five word passphrase provides a level of security much higher than the simple passwords most people use. We recommend a minimum of six words for use with GPG, wireless security and file encryption programs. A seven, eight or nine word passphrase is recommended for high value uses such as whole disk encryption, BitCoin, and the like. For more information, see the Diceware FAQ . Now roll the dice and write down the results on a slip of paper. Write the numbers in groups of five. Make as many of these five-digit groups as you want words in your passphrase. You can roll one die five times or roll five dice once, or any combination in between. If you do roll several dice at a time, read the dice from left to right. Look up each five digit number in the Diceware list and find the word next to it. For example, 21124 means your next passphrase word would be "clip" (see the excerpt from the list, above). When you are done, the words that you have found are your new passphrase. Memorize them and then either destroy the scrap of paper or keep it in a really safe place. That's all there is to it!

Example

Suppose you want a six word passphrase, as we recommend for most users. You will need 6 times 5 or 30 dice rolls. Let's say they come out as:

1, 6, 6, 6, 5, 1, 5, 6, 5, 3, 5, 6, 3, 2, 2, 3, 5, 6, 1, 6, 6, 5, 2, 2, 4, 6, 4, 3, 2, and 6.

Write down the results on a scrap of paper in groups of five rolls:

1 6 6 6 5 1 5 6 5 3 5 6 3 2 2 3 5 6 1 6 6 5 2 2 4 6 4 3 2 6

You then look up each group of five rolls in the Diceware word list by finding the number in the list and writing down the word next to the number:

1 6 6 6 5 cleft 1 5 6 5 3 cam 5 6 3 2 2 synod 3 5 6 1 6 lacy 6 5 2 2 4 yr 6 4 3 2 6 wok

Your passphrase would then be:

cleft cam synod lacy yr wok

Some Tips



For maximum security make sure you are alone and close the curtains. Write on a hard surface – not on a pad of paper. After you memorize your passphrase, burn your notes, pulverize the ashes and flush them down the toilet.

If you are using a passphrase for file encryption, we recommend you keep a copy written down in a safe place. If you don't and you forget your passphrase, your files are lost forever.

If you want to work from a printed copy of the English word list, download the the Diceware word list in PDF format or PostScript format. These files are formatted with 4 columns and 54 lines per page. You will get a neat, 36 page printout in which the first two dice throws are the same for each page. This makes look-ups especially easy. If you prefer a more compact printout, here is an 11-page version from Patrick Feisthammel. Be careful not to mark the printed copy in any way while you are selecting words. You can also find the word list as an Appendix to Internet Secrets.

If you need to make up passphrases often, get a shoe box or a food storage box about the same size. Put five dice in the box, shake them up vigorously – at least ten hard shakes – and then tip the box to let all the dice slide down to one edge. Now open the box, read the dice from left to right, or front to back if a few line up. Then just look up the corresponding word list entry. Repeat this process until you have enough words for your passphrase.

We recommend that you use the passphrase exactly as generated. If you want a stronger passphrase, select an additional word using the diceware method.

Because some words on the diceware list are two characters or less, you can get a very short passphrase. If your passphrase, including the spaces between the words, is less than 19 characters long, we recommend that you start over and create a new passphrase. You should also start over if your passphrase is a recognizable sentence or phrase in the language you are using. (These situations are extremely rare.) See the Diceware FAQ for suggestions on how to memorize your passphrase.

Optional stuff you don't really need to know

For extra security without adding another word, insert one special character or digit chosen at random into your passphrase. Here is how to do this securely: Roll one die to choose a word in your passphrase, roll again to choose a letter in that word. Roll a third and fourth time to pick the added character from the following table:

Third Roll 1 2 3 4 5 6 F 1 ~ ! # $ % ^ o 2 & * ( ) - = u 3 + [ ] \ { } r 4 : ; " ' < > t 5 ? / 0 1 2 3 h 6 4 5 6 7 8 9



For the technically inclined, each word in your Diceware passphrase yields 12.9 bits of entropy, the way passphrase security is measured. A five word Diceware passphrase would have an entropy of at least 64.6 bits; six words would have 77.5 bits, seven words 90.4 bits, eight words 103.2 bits. Inserting a letter at random adds about 10 bits of entropy. All this assumes, of course, that you actually keep your passphrase a secret. You'll find a lot more information you don't really need to know in the Diceware FAQ.

Why Diceware™?

There are many different recommendations available on the Internet about how to pick a passphrase. Some are good, a few are bad, but almost all require the user to judge what will be hard for someone else to guess. Some give no guidance on how to do that, others have you make complex mathematical calculations. By contrast, the Diceware method of generating passphrases is:



Easy to learn and use

Very secure

Totally prescriptive – we tell you exactly what to do at each step of the process

Transparent – there are no "trust me"s Free – there is no computer software or hardware required, just the Diceware wordlist and some ordinary dice

The prescriptive nature of Diceware is very important for new users of encryption. Here is one person's experience, as posted to the Internet newsgroup alt.security.pgp:

"I just wanted to relate a personal story about how hard it is to convince a novice how important it is to select a secure password, and get them to understand what constitutes a secure password. I am an old-timer at both the Internet and security issues. My sister, however, is brand new to it having just opened an Internet account. She lives in [the mid-west] while I live [on the west coast]. As a result, we exchange quite a bit of very personal email.

Recently, she wanted to give her Internet password to her husband so that he could get on line. However, she still wanted to be able to exchange private messages with me that he would not be able to read. I, of course, introduced her to PGP.

I gave her the usual lecture about how important it is to select a password that nobody else can easily guess, and that the ideal password would be some obscure and nonsense word that would have meaning only to her. I told her all about not selecting birthdays, anniversaries, names, and the like. I didn't suggest a random combination of letters and numbers because we were not after world class security, we just wanted to keep her husband out of our private letters. So, after she selected her PGP password, I decided to give it a try at cracking it. The VERY FIRST password I tried worked! She was totally surprised at how easily I had found it, but it was a word that anyone knowing her would have access to. So, after giving her some more tips on good password selection, I let her try again. This time, it took me only 3 attempts before I found the right word. Finally, she gave up and let me pick a password for her."

Had she used Diceware, the author's sister's very first passphrase would have been totally secure and known only to her. Remember: in public key cryptography, the security of your message depends on the recipient's passphrase. Spread the word about Diceware!

Links And References

For more information on passphrases and Diceware™ see the following:

Diceware FAQ Questions and answers for people who want to know more about Diceware and passphrase generation.

Diceware Word List, the list in PostScript format, Beale word list, Diceware8k list for computer generation

A Survey of PGP Passphrase Usage A small poll I ran to find out what PGP users actually do to make passphrases, and some suggestions for improvement.

Diceware for Passphrase Generation and Other Cryptographic Applications Includes info on other uses of Diceware and an analysis of Diceware security.

NIST Special Publication 800-63B Digital Identity Guidelines, Authentication and Lifecycle Management, June 2017 edition updates recommendations on password and passphrase usage, especially section 5.1.1.

Protecting Passwords by Gary McGraw and John Viega, An article in the IBM Developerworks Security Library that discuss passwords, pasphrases and Diceware.

Passgen: A Password Generator Java Applet Uses keyboard latency to generate random passwords based on a selectable format. Not as secure as the diceware method, but adequate for login passwords and similar applications. Includes source code.

Random Noise Sources A collection of information on sources of randomness for use with computers.

CipherSaber Home Page Learn how to build your own strong encryption program. It's easier than you think!

Other Papers on Cryptography by Arnold Reinhold P=?NP -- who Cares?, Cryptanalysis of Histocompatibility, etc.

S. N. Porter, A Password Extension for Improved Human Factors,

Advances in Cryptology: A Report on CRYPTO 81, Allen Gersho, editor, volume 0, U.C. Santa Barbara Dept. of Elec. and Computer Eng., Santa Barbara, 1982. Pages 81--81. Also in Computers & Security, Vol. 1. No. 1, 1982, North Holland Press.

BG -- Bulgarian word lists (PDF) provided by yradunchev under the terms of the CC-BY-4.0 license. Here is a sample Bulgarian passphrase:

дави федрос успеем корков кле мамон

CA -- Catalan word lists (ASCII and UTF-8) provided by Marcel Hernandez under the terms of the CC-BY-4.0 license. Here is a sample Catalan passphrase:

radiar balca imaginar insula sinitizin dar

CN – Chinese page and word list translated by Lian, and Chinese word lists at Github, provided by Chenfeng Bao, under GNU General Public License v3.0. Here is a sample passphrase with Pinyin romanization (a Wubi wordlist is also available):

qingfu 情妇 juzhao 剧照 zugou 足够 xiabo 下拨 huode 获得 fanpan 反叛

CZ -- Czech word list provided by Vladimír Sedmík and a version in pdf, both under the GNU General Public License. Czech grammar is highly inflected and Vladimír says all the words in the list are in the basic shape; using varied shapes in your passphrase can increase security. Here is a sample passphrase:

tchán krab chabý ničení nářek jezdit

DA -- Danish word list provided by Povl Falk-Jensen Here is a sample Danish passphrase:

odf simse gnid khmer bejae info

DE – German word list ( PDF version ) provided by Benjamin Tenne under the terms of the GNU General Public License. A modified version with 22 potentially offensive words replaced has been suggested by Simon Klima. Here is a sample German passphrase:

distel ist landen kammer puffen nutze

EO – Esperanto page and word list translated by Makis Diras, including a Esperanto word list. Here is a sample Esperanto passphrase:

hirt neŭtr livre etern krank esoter

ES – Spanish page and word list translated by Manuel Palao, including a Spanish word list. Here is a sample Spanish passphrase:

multa h64 quien enero tubo

ET – Estonian word list (PDF format) for Täringvara (Diceware in Estonian) provided by Kaarel Pärtel under the terms of the CC-BY-4.0 license. Here is a sample Estonian passphrase:

koonal eesti aedik kumbki las umbri

EU – Basque (Euskara) word list (PDF format) provided by Aitor Fraile Azcue under the terms of the CC-BY-4.0 license. Here is a sample Basque passphrase:

kasta ahaztu kaier sistema usu jorran

FI ---Finnish page and word list translated by Kai Puolamaki, including a Finnish word list. Here is a sample Noppaware ("noppa" means a dice in Finnish) passphrase:

olli kukot hoveli hintaa airoja

FR – French page and word list translated by Joachim Dubuquoy-Portois. There is a French word list by Matthieu Weber, in several formats. Sample:

ileus humide diktat sbire peotte

HU – Hungarian (Magyar Nyelv) word list (PDF format) provided by Soma Lucz under the terms of the CC-BY-4.0 license. Here is a sample Hungarian passphrase:

valko ujjas gatai rezez erfet hivan

IW – Hebrew word list provided under the terms of the CC-BY-4.0 license. Here is a sample Hebrew passphrase:

חשובה לקס קארה מקדם הרעש עוגה

IT – Italian page and word list translated by Tarin Gamberini with an Italian word list (pdf format). Here is a sample Italian passphrase:

casi botole stadi maglia venivo

JP – Japanese page and word list translated by Hiroshi Yuki, with a Japanese wordlist in Romaji by J Greely. Here is a sample Japanese passphrase:

douse aho socchi bidou tosou ob

LA -- Latin word list provided by Sebastian Możejko under a CC-BY license. Here is a sample Latin passphrase:

deceat tenuere tali petebat ideis paterno

MI -- Maori word list provided by Rangi Kemara under a CC-BY license. Here is a sample Maori passphrase:

iatoto okaoka arawai takawa unene takoru

NO -- Norwegian word list provided by Willy T. Koch under a CC-BY license. Here is a sample Norwegian passphrase:

kare puben aks snuse dulle sauen

NL -- Dutch word list provided by Bart Van den Eynde under the terms of the GNU Free Documentation License. Here is a sample Dutch passphrase:

ijler 100 leperd akolei kolkje Alternative CC-BY licensed Dutch word lists by Remko Tronçon, with words he says are easier to remember. Sample: losjes rog teef hoor boost glazig

PL – Polish page and word list translated by Piotr (DrFugazi) Tarnowski, Computer Science Techniques Centre, University of Silesia, Katowice, PL, including a Polish word list. Here is a sample Polish passphrase:

plewka szpieg raban pruski ibi

PT – Portuguese word list translated by Patxi Pierce. Here is a sample Portuguese passphrase:

curso franja obeso berne perigo liquen

RO - Romanian word list created by Alex Danciu, and PDF versions. Here is a sample Romanian passphrase:

bidibiu rebut jordie dor ebraic lip

RU -- Russian word list provided by "kitten," and a version in rtf. Here is a sample passphrase:

кома жилет лысун кроль ерник вскрик

SK -- Slovak word list provided by Juraj Tomori under the MIT License. Here is a sample Slovak passphrase:

inému odlišuje čeliť tureckej zväzom lietadlom

SL -- Slovenian word list provided by Gašper Kozlovič (also in .ods format). Here is a sample Slovenian passphrase:

stotič učen obod snop diskus ovreči

SV -- Swedish word list provided by Magnus Bodin. Here is a sample Swedish passphrase:

ark altan rodel lamm kyot

TR -- Turkish word list provided by Mert Dirik. Here is a sample Turkish passphrase:

derz permi turba um beniz

• The Diceware Kit contains instructions on how to create a Diceware word list for other languages.

Special thanks to all the translators!

Other English word lists

A number of other groups are developing word lists for generating passphrases. In July 2016, the Electronic Frontier Foundation (EFF) published a new list. Their long list contains 7776 words, so its security is exactly the same as the Diceware word list. “The words in our [the EFF's] list are longer (7.0 characters) on average, than Reinhold's Diceware list (4.3 characters). This is a result of banning words under 3 characters as well as prioritizing familiar words over short but unusual words.” Here is a sample random EFF passphrase:

foundling confess henna figure congrats revival

We still think having a short passphrase is worth the bother of learning an unfamiliar word or remembering simple strings such as nnnn or xg, but the choice is purely a matter of taste, not security. Note that the EFF says it has screened its word list to remove all potentially offensive words. I attempted to excluded the worst obscenities and racial slurs, but there are words in my list that have dual meanings in English slang and it is possible that a randomly generated passphrase could have offensive meaning. Pick a word list that works for you.

For more information on PGP see:

The GNU Privacy Guard (GPG), an open source implementation of PGP

OpenPGP OpenPGP Working Group with links to other PGP-compatible software.

Tutorial for beginners to PGP, Bernard John Poole, University of Pittsburgh at Johnstown

Here are some other sites with recommendations on how to make your passphrase. I do not suggest that the information at these sites is wrong, just that it may be too complex for most people. Take a look and judge for yourself.

Passphrase FAQ by Randall T. Williams

Passphrase FAQ by Grady Ward

Symantec Corp., which acquired PGP in 2010

Ascii key+ || 08d0a5d961603380e2949d682c 10 Byte IV || bfe8da5c1dec3aba9725d4f689 Ron's No.4 || 40761763d4d38935e8bd8a44bf All u need ==== 4656a7bd7f9ae5d082a30cdfa7 CipherSaber || f21a918d29c5917956d0468eaf

http://ciphersaber.org/ Learn how to write a simple yet strong encryption program of your own. If you have any programming skills at all you can do it.

Help support this page by buying books I worked on. They make great gifts!

Switching to a Mac For Dummies,

banging your head against a wall--it feels so good when you stop,

Green IT for Dummies,

chock full of useful information that can save the planet,

and

Internet Secrets, 2nd ed

with chapters by me on cryptography and Diceware, including the Diceware wordlist.

If you can't find them at your local bookstore, click on the titles to order them directly, in association with Amazon.com.







Arnold G. Reinhold

Electronic mail to my initials (three letters) a.t.sign mac dot com

Copyright © 1995-2020, Arnold G. Reinhold, Cambridge, Massachusetts USA.

The author hereby grants rights for free, non-commercial, electronic distribution, with attribution, of this entire text under the terms of the Creative Commons CC-BY-NC-ND 3.0 license. Linking to this page or the word lists, including for commercial use, is permitted and encouraged. All other rights reserved. Reasonable requests for other uses, such as translations, are encouraged and will be carefully and promptly considered. This information is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

To the extent that a word list is protected by copyright, A G Reinhold licenses its rights to the English Diceware Wordlist under the Creative Commons CC-BY 4.0 license. Other word list licenses are noted above.

Diceware is a trademark of A G Reinhold.

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First published on usenet's sci.crypt.research on 1995-8-1.

Last updated 2020-5-14





