BaseHash is a small library for creating reversible obfuscated identifier hashes to a given base and length. The project is based on the GO library, PseudoCrypt by Kevin Burns. The library is extendible to use custom alphabets and other bases.
The library uses golden primes and the Baillie-PSW primality test for hashing
to n length. From testing, I have gotten base62 up to 171 in length.
Maximum number is Base^Length - 1.
-> 62^171 - 1 or 315485137315301582773830923281251564555089304044116975095028710
008180170985809814948409129256031320171601473029340987051144213
425607224233134700199050224309707192084206558324823774511143549
765069844412467187455459156942237963528166277256376429656681225
8180788198965409784329587392583208081351811265973977087
pip install basehash
nosetests tests/
import basehash
base62 = basehash.base62()
encoded = base62.encode(2013)
decoded = base62.decode('WT')
print encoded, decodedWT 2013
import basehash
base62 = basehash.base62()
hashed = base62.hash(2013, 8)
unhashed = base62.unhash('6LhOma5b')
print hashed, unhashed6LhOma5b 2013
The GENERATOR variable uses the golden ratio, 1.618033988749894848, to get
the next highest prime of base ** number * generator. This can be overridden
within the base classes.
import basehash
base62 = basehash.base62(1.75) # base62(generator=1.75)import basehash
alphabet = basehash.generate_alphabet(basehash.BASE36, randomize=20)
# runs random.shuffle on basehash.BASE36 (randomize)=20 times.
# produces something like: L0RJBY2HQ7MSGXPE6NCUW38KAFVDO51IZ94T
# save this alphabet to use for hasher.unhash()
hasher = basehash.base(alphabet, length=10)There is a maximum number while hashing with any given base. To find out what
this number is, we use the Base^Length - 1.
import basehash
base36 = basehash.base36()
print base36.maximum_value(12) # or base36.maximum(length)4738381338321616895
So with the max number for base36 at length 12 as 4738381338321616895 we
get the following:
import basehash
base36 = basehash.base36()
hash = base36.hash(4738381338321616895, 12)
# 'DR10828P4CZP'
hash = base36.hash(4738381338321616896, 12)
# ValueError: Number is too large for given length. Maximum is 36^12 - 1.Extending is made easy with some time spent determining the next highest prime dynamically, the fastest possible that I have been able to make it so far.
import basehash
custom = basehash.base('24680ACEGIKMOQSUWYbdfhjlnprtvxz')
print custom.encode(2013) # 66x
print custom.decode('66x') # 2013
print custom.hash(2013, 8) # 8AQAQdYd
print custom.unhash('8AQAQdYd') # 2013
print custom.maximum_value(12) # 787662783788549760