  In a democratic setting, we introduce a commitment scheme which allows for
transparent validation of transfers and reversible delegations of voting power
between citizens without sacrificing their privacy. A unit of voting power is
publicly represented by the Merkle root of a tree consisting of its latest
owner's public key, a random nonce and the Merkle root of the tree of its
previous owner's public key and random nonce and so on. A transition includes
the input units, their owner's public keys and signatures, the hashes of their
nonces and the output units generated with the new owners' public keys and
random nonces. In case of a delegation, the receiver provides the sender with
the hashed random nonces and hashed public keys for the output units. In case
of a transfer, only the precomputed output units are provided by the receiver.
In a reversal, a historical owner reveals the hashes of the nonces and public
keys that resulted in the subsequent units. To vote, the owner reveals the
actual nonces and public keys.
