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Description:

hippiepug 0.5.0

hippiepug

Sublinear-lookup blockchains and efficient key-value Merkle trees.
Check out the documentation.

This library provides implementations of two cryptographic data structures:

Blockchains with log(n) sublinear traversal, implemented as high-integrity
deterministic skip-lists (skipchains). In this kind of blockchain verifying
that block b extends block a does not require to download and process
all blocks between a and b, but only a logarithmic amount of them.
Verifiable dictionary, implemented as a key-value Merkle tree that
guarantees unique resolution. A proof of inclusion of a key-value pair in
such a tree also proves that there does not exist another value for a given
key somewhere else in the tree.

Both are meant to be used with a content-addressable storage. Each data
structure supports logarithmic queries, and logarithmic proofs of inclusion:

Retrievals per lookup
Inclusion proof size
Append

Skipchain
O(log(n))
O(log(n))
O(1)

Key-value Merkle tree
O(log(n))
O(log(n))
Immutable

with n being the size of the dictionary, or the number of blocks in the
case of a chain.
The theoretical details are in the paper.

Getting started
You can install the library from PyPI:
pip install hippiepug
Then, the easiest way to run the tests is:
python setup.py test
Be sure to check out the usage guide.

Acknowledgements

The library is a reimplementation of G. Danezis’s hippiehug (hence
the name).
This work is funded by the NEXTLEAP project within the European Union’s
Horizon 2020 Framework Programme for Research and Innovation (H2020-ICT-2015,
ICT-10-2015) under grant agreement 688722.
The hippie pug logo kindly donated by M. Naiem.