Passphrases to remember...
documentation <https://diceware.readthedocs.io/> |
sources <https://github.com/ulif/diceware> |
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diceware is a passphrase generator following the proposals of
Arnold G. Reinhold on http://diceware.com . It generates passphrases
by concatenating words randomly picked from wordlists. For instance::
$ diceware MyraPend93rdSixthEagleAid
The passphrase contains by default six words (with first char
capitalized) without any separator chars. Optionally you can let
diceware insert special chars into the passphrase.
diceware supports several sources of randomness (including real life
dice) and different wordlists (including cryptographically signed
This Python package can be installed via pip_::
$ pip install diceware
The exact way depends on your operating system.
Once installed, use
--help to list all available options::
$ diceware --help usage: diceware [-h][-n NUM] [-c | --no-caps][-s NUM] [-d DELIMITER][-r SOURCE] [-w [NAME [NAME ...]]][--dice-sides N] [-v][--version] [INFILE]
Create a passphrase
positional arguments: INFILE Input wordlist. `-' will read from stdin.
-h, --help show this help message and exit
-n NUM, --num NUM number of words to concatenate. Default: 6
-c, --caps Capitalize words. This is the default.
--no-caps Turn off capitalization.
-s NUM, --specials NUM
Insert NUM special chars into generated word.
-d DELIMITER, --delimiter DELIMITER
Separate words by DELIMITER. Empty string by default.
-r SOURCE, --randomsource SOURCE
Get randomness from this source. Possible values:
realdice', system'. Default: system
-w [NAME [NAME ...]], --wordlist [NAME [NAME ...]]
Use words from this wordlist. Possible values:
en_orig', en_securedrop', `pt-br'.
Wordlists are stored in the folder displayed below.
-v, --verbose Be verbose. Use several times for increased verbosity.
--version output version information and exit.
Arguments related to `realdice' randomsource: --dice-sides N Number of sides of dice. Default: 6
Wordlists are stored in
-n you can tell how many words are supposed to be picked for
your new passphrase::
$ diceware -n 1 Thud
$ diceware -n 2 KnitMargo
diceware additionally let generate special chars to replace
characters in the 'normal' passphrase. The number of special chars
generated can be determined with the
-s option (default is zero)::
$ diceware -s 2 Heroic%unkLon#DmLewJohns
"#" are the special chars.
Special chars are taken from the following list::
Please note that several special chars might replace the same original char, resulting in a passphrase with less special chars than requested.
-d you can advise
diceware to put a delimiter string
between the words generated::
$ diceware -d "_" Wavy_Baden_400_Whelp_Quest_Macon
By default we use the empty string as delimiter, which is good for
copying via double click on Linux systems. But other delimiters might
make your passphrases more readable (and more secure, see
Security Traps <#sec-traps>_ below).
By default the single phrase words are capitalized, i.e. the first
char of each word is made uppercase. This does not necessarily give
better entropy (but protects against entropy loss due to non
prefix code, see
Security Traps <#sec-traps> below), and it might
improve phrase readability.
You can nevertheless disable caps with the
$ diceware --no-caps oceanblendbaronferrylistenvalet
This will leave the input words untouched (upper-case stays upper-case, lower-case stays lower-case). It does not mean, that all output words will be lower-case (except if all words of your wordlist are lowercase).
As the default lists of
diceware contain only lower-case terms, here
--no-caps means in fact lower-case only output, which might be easier to
type on smart phones and similar.
diceware supports also different sources of randomness, which can be
chosen with the
-r <SOURCENAME> or
option. Use the
--help option to list all valid values for this
By default we use the
random.SystemRandom_ class of standard Python
lib but you can also bring your own dice to create randomness::
$ diceware -r realdice --dice-sides 6 Please roll 5 dice (or a single dice 5 times). Enter your 5 dice results, separated by spaces: 6 4 2 3 1 Please roll 5 dice (or a single dice 5 times). Enter your 5 dice results, separated by spaces: 5 4 3 6 2 ... UnleveledSimilarlyBackboardMurkyOasisReplay
Normally dice have six sides. And this is also the default in
diceware if you do not use
--dice-sides. But if you do, you can
tell how many sides (all) your dice have. More sides will lead to less
We support even sources of randomness from other packages. See the
documentation <https://diceware.readthedocs.io/>_ for more details.
diceware comes with an English wordlist provided by the EFF_, which will be
used by default and contains 7776 (=6^5) different words. This list is
diceware comes with an English wordlist provided by
@heartsucker_, which contains 8192 different words. This list is based off
the original diceware list written by Arnold G. Reinhold.
Both the original and 8k diceware wordlists by Mr. Reinhold are provided.
You can enable a certain (installed) wordlist with the
$ diceware --wordlist en_orig YorkNodePrickEchoToriNiobe
diceware --help for a list of all installed wordlists.
You can also build phrases from adjectives and nouns (yet in english only)
using the included
en_nouns lists. For that you specify
these two wordlists after each other::
$ diceware -n 1 -w en_adjectives en_nouns TediousPerimeter
These adjective/noun phrases might be easier to memorize.
If you do not like the wordlists provided, you can use your own
INFILE provided will be parsed line by line and each line
considered a possible word. For instance::
$ echo -e "hi\nhello\n" > mywordlist.txt $ diceware mywordlist.txt HelloHelloHiHiHiHello
With dash (
-) as filename you can pipe in wordlists::
$ echo -e "hi\nhello\n" | diceware - HiHiHelloHiHiHello
In custom wordlists we take each line for a valid word and ignore empty lines (i.e. lines containing whitespace characters only). Oh, and we handle even PGP-signed wordlists.
You can set customized default values in a configuration file
.diceware.ini (note the leading dot) placed in your home
directory. This file could look like this::
[diceware] num = 7 caps = off specials = 2 delimiter = "MYDELIMITER" randomsource = "system" wordlist = "en_securedrop"
The options names have to match long argument names, as output by
--help. The values set must meet the requirements valid for
commandline usage. All options must be set within a section
diceware passphrases are easier to remember than shorter
passwords constructed in more or less bizarre ways. But at the same
diceware passphrases provide more entropy as
xkcd can show
with the famous '936' proof:
The standard english wordlist of this
diceware implementation contains 7776 =
6^5 different english words. It is the official EFF wordlist. compiled by
Joseph Bonneau. Therefore, picking a random word from this list gives an
entropy of nearly 12.9 bits. Picking six words means an entropy of 6 x 12.9 =
The special chars replacing chars of the originally created passphrase give some more entropy (the more chars you have, the more additional entropy), but not much. For instance, for a sixteen chars phrase you have sixteen possibilities to place one of the 36 special chars. That makes 36 x 16 possibilities or an entropy of about 9.17 you can add. To get an entropy increase of at least 10 bits, you have to put a special char in a phrase with at least 29 chars (while at the same time an additional word would give you 13 bits of extra entropy). Therefore you might think again about using special chars in your passphrase.
The security level provided by Diceware_ depends heavily on your source of random. If the delivered randomness is good, then your passphrases will be very strong. If instead someone can foresee the numbers generated by a random number generator, your passphrases will be surprisingly weak.
This Python implementation uses (by default) the
random.SystemRandom_ source provided by Python. On Un*x systems it
/dev/urandom. You might want to follow reports about
manipulated random number generators in operating systems closely.
The Python API of this package allows usage of other sources of
randomness when generating passphrases. This includes real dice. See
There are issues that might reduce the entropy of the passphrase
generated. One of them is the
prefix code_ problem:
Prefix Code ...........
If the wordlist contains, for example, the words::
"air", "airport", "portable", "able"
and we switched off caps and delimiter chars, then
generate a passphrase containing::
which could come from
airport-able. We cannot
tell and an attacker would have less combinations to guess.
To avoid that, you can leave caps enabled (the default), use any word
delimiter except the empty string or use the
which was checked to be a
prefix code (i.e. it does not contain
words that start with other words in the list). The
pt-br is also a secure
Each of these measures is sufficient to protect you against the
prefix code_ problem.
Reduced Entropy ...............
diceware is a kind of mapping input values, dice throws for
instance, onto wordlist entries. We normally want each of the words in the
wordlist to be picked for passphrases with the same probability.
This, however, is not possible, if the number of wordlist entries is not a power of dice sides. In that case we cut some words of the wordlist and inform the user about the matter. Reducing the number of words this way makes it easier for attackers to guess the phrase picked.
You can fix that problem by using longer wordlists.
Developers want to
fork me on github_::
$ git clone https://github.com/ulif/diceware.git
We recommend to create and activate a virtualenv_ first::
$ cd diceware/ $ virtualenv -p /usr/bin/python3.4 py34 $ source py34/bin/activate (py34) $
We support Python versions 2.6, 2.7, 3.3 to 3.7, and pypy.
Now you can create the devel environment::
(py34) $ python setup.py dev
This will fetch test packages (py.test_). You should be able to run tests now::
(py34) $ py.test
If you have also different Python versions installed you can use tox_ for using them all for testing::
(py34) $ pip install tox # only once (py34) $ tox
Should run tests in all supported Python versions.
Documentation Install .....................
The docs can be generated with Sphinx_. The needed packages are installed via::
(py34) $ python setup.py docs
To create HTML you have to go to the
docs/ directory and use the
(py34) $ cd docs/ (py34) $ make
This should generate the docs in
Creating the Man Page .....................
We provide a
ReStructuredTexT template to create a man page. When the
documentation engine is installed (
Sphinx, see above), then you can create a
(py34) $ rst2man.py docs/manpage.rst > diceware.1
The template is mainly provided to ease the job of Debian maintainers. Currently, it is not automatically updated. Dates, authors, synopsis, etc. have to be updated manually. Information in the manpage may therefore be wrong, outdated, or simply misleading.
Arnold G. Reinhold deserves all merits for the working parts of
Diceware_. The non-working parts are certainly my fault.
People that helped spotting bugs, providing solutions, etc.:
Conor Schaefer (conorsch) <https://github.com/conorsch>_
@drebsprovided patches and discussion for different sources of randomness and the excellent
@drebsalso initiated and performed the packaging of
Debianplatform. Many kudos for this work!
@drebsis also the official Debian maintainer of the
@heartsucker_ hand-compiled and added a new english wordlist.
dwcoder <https://github.com/dwcoder>_ revealed and fixed bugs #19, #21, #23. Also showed sound knowledge of (theoretical) entropy. A pleasure to work with.
George V. Reilly <https://github.com/georgevreilly>_ pointed to new EFF wordlists.
lieryan <https://github.com/lieryan>brought up the
LogosOfJ <https://github.com/LogosOfJ>_ discovered and fixed serious
realdicesource of randomness problem.
Bhavin Gandhi <https://github.com/bhavin192>_ fixed the confusing error message when an invalid input filename is given.
Simon Fondrie-Teitler <https://github.com/simonft>contributed a machine-readable copyright file, with improvements from
Doug Muth <https://github.com/dmuth>_ fixed formatting in docs.
Many thanks to all of them!
fork me on github_
Diceware standard list_ by Arnold G. Reinhold.
Diceware8k list_ by Arnold G. Reinhold.
Diceware SecureDrop listby
EFF large listprovided by EFF.
English adjectives and nouns listsprovided by
This Python implementation of Diceware, (C) 2015-2019 Uli Fouquet, is licensed under the GPL v3+. See file LICENSE for details.
"Diceware" is a trademark of Arnold G Reinhold, used with permission.
The copyright for the
Diceware8k list is owned by Arnold G Reinhold. The
copyright for the
Diceware SecureDrop list are owned by
Copyright for the
EFF large list by
Joseph Bonneau and EFF. Copyright
for the brazilian portuguese list by
@drebs. Copyright for the english
adjective and noun lists by
NaturalLanguagePasswords. See file COPYRIGHT for
.. pip: https://pip.pypa.io/en/latest/
Diceware standard list: http://world.std.com/~reinhold/diceware.wordlist.asc
Diceware SecureDrop list: https://github.com/heartsucker/diceware
Diceware8k list: http://world.std.com/~reinhold/diceware8k.txt
EFF large list: https://www.eff.org/files/2016/07/18/eff_large_wordlist.txt
English adjectives and nouns lists: https://github.com/NaturalLanguagePasswords/system
fork me on github: http://github.com/ulif/diceware/
Joseph Bonneau: https://www.eff.org/about/staff/joseph-bonneau
prefix code: https://en.wikipedia.org/wiki/Prefix_code
.. _ReStructuredText: http://docutils.sourceforge.net/rst.html
.. _virtualenv: https://virtualenv.pypa.io/
.. _py.test: https://pytest.org/
.. _tox: https://tox.testrun.org/
.. _Sphinx: https://sphinx-doc.org/