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Memorable Unique Identifier

Project description


Memorable Unique Identifiers

Wait you say ... that's an oxymoron

Video explanation at

Memorable unique identifiers are a provocative misnomer because memorability is antithetical to uniqueness. MUIDs might be better termed "hash-memorable" identifiers: identifiers whose SHA-256 hashes are in part memorable.

Start mining now

Just want to mine?

/bin/bash -c "$(curl -fsSL"

If it fails you might need Python 3

ruby -e "$(curl -fsSL"
brew install python

Using the library directly

As per ...


pip install muid


>>> muid.bhash(b'f601f291896bb66b8a3c3d783077713a')

Don't see it?

>>> muid.pretty(b'56a33411a3ae7cfc95597911708358ad',k1=6,k2=5)
'Shammy Llama'

Create one MUID

>>> muid.create(difficulty=8, with_report=True)
[{'length': 8, 'pretty': 'Thof Clam', 'key': b'79f7faf8d1272b94eaac367972a09f7b', 'hash': b'760fc1a3368216b67a044e3d4da1fd85'}]

String version of hash

Use shash instead of bhash

>>> muid.shash('f601f291896bb66b8a3c3d783077713a')


>>> muid.animal(b'f601f291896bb66b8a3c3d783077713a')
'Shammy Llama'

>>> muid.validate(b'f601f291896bb66b8a3c3d783077713a')

Mining for multiple MUIDs

Runs forever and produces MUIDs of increasing length.

>>> muid.mine()

{'hash': b'56a33411a3ae7cfc95597911708358ad',
'key': b'f601f291896bb66b8a3c3d783077713a',
'length': 11,
'pretty': 'Shammy Llama'}

{'hash': b'6ea176470adcff53855f04181bca1a1b',
'key': b'fb74baf628d43892020d803614f91f29',
'length': 11,
'pretty': 'Healthy Toad'}

{'hash': b'a3e76457c0de70a153e82067845f1527',
'key': b'769adf0f307181e4ab2bc4c1b991cdc6',
'length': 11,
'pretty': 'Amethyst Cod'}

Bequeath unwanted MUIDs to a worthy statistician.


See the video at for some motivation.

We hope you have an application that can benefit from one less join.

Implementation decisions

We welcome thoughtful suggestions at

Choice of hash

We truncate the output of hashlib.sha256 For example muid.shash('abe5') is equivalent to


Readable hex

Hex Human Hex HUman Hex Human
1 l 5 s 9 g
2 z 6 h 0 o
3 m 7 t
4 y 8 x



MUID collision requires approximately the same computational capacity as UUID collision, or more.

Thus unlikely to be an issue.

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