@ -11,7 +11,11 @@ This book assumes basic knowledge of the Bitcoin protocol, Bitcoin source code,
C++ and basic compiler knowledge. No prior knowledge of Hush is assumed, this
work contains a basic introduction of Hush features.
# High Level Overview of KMD DPoW
# High Level Overview of Hush DPoW
Delayed Proof-of-Work is a general concept and the Hush Developers have implemented
a production system which implements the algorithm for HUSH and for any blockchains
which want to pay HUSH for the service of double spend protection.
DPoW sends blockhash data from your coin, to potentially another coin like HUSH, which is then sent to Bitcoin,
providing a small coin with a small hashrate the security of BTC hashrate. This
@ -29,12 +33,12 @@ globe. They are not in any one physical location, which makes the system
resilient against a datacenter outage or natural disaster in one geographical
location. The algorithm NNs use require 13 notary nodes to come together and
agree on what the latest Merkle root and other metadata that will be embedded
into the Komodo and Bitcoin blockchains inside the OP\_RETURN data of a
into the Hush and Bitcoin blockchains inside the OP\_RETURN data of a
multisig transaction. This means that to take down the notarization process, to
stop the data flow, one must attack and knock offline 52 different servers in
diverse locations, simultaneously. In this case, notarization data would stop
flowing, but no "fake" or "incorrect" notarization data can be created, because
the source code of Komodo has the public keys of notary nodes embedded inside.
the source code of Hush has the public keys of notary nodes embedded inside.
Only notary nodes have the corresponding private keys to make transactions that
the network will trust as valid notarizations. So DDoS attacks can only stop
@ -48,30 +52,6 @@ they require a coordinated effort of all exchanges/mining pools/users upgrading,
since it is a hard fork. Take this into consideration when planning upgrade
timelines.
## Yearly Hard Forks
Every year Komodo does a hard fork, which coincides with electing new notaries,
which usually happens in early May. Electing new notaries means changing the
KMD source code to list these new pubkeys and removing old ones. This means
that any coin using DPoW will *also need to hardfork at a coordinated time*,
i.e. coins using DPoW will also fork in May each year, after new KMD notaries
have been elected and the new notarization season begins.
Coins can turn this yearly hard-fork into an opportunity to make any other
non-emergency changes that would be consensus-level hard-forks. It allows
a yearly upgrade window for each coin, where a hardfork is going to happen
anyway. For instance, the size of the maximum OP\_RETURN might be changed,
or a different difficulty algorithm used (test it thoroughly first!).
Additionally, there is a preferred time of year where it makes the most sense
to integrate DPoW, essentially directly after the yearly KMD notary election
and hard-fork. That prevents a situation where adding DPoW integration in March
requires a hard-fork and then the KMD notary election requires another
hard-fork just a short-time later. Exchanges are not excited to update full
nodes and some exchanges attempt to charge for full node updates (which the
author finds scammy), so timing the integration of DPoW services can be very
strategic.
# DPOWconfs protect against double spends with no code changes
A recent innovation called "DPoW confs" allows
@ -100,8 +80,8 @@ are protected by default.
# Cost of DPoW
The raw cost of 64 global notary nodes making transactions roughly once per
minute (the Komodo block interval) and continually on other coins has a cost.
The raw cost of many, say 64 global notary nodes making transactions roughly once every
75 seconds (the Hush block interval) and continually on other coins has a cost.
Various costs related to DPoW can be broken down into these categories:
@ -117,7 +97,7 @@ Chain](https://github.com/MyHush/hush-smart-chains), there are no integrations n
the cost for notarization transactions. This can be accomplished by doing an
airdrop from your current chain to a new Hush Smart Cain, where people use their
private keys to unlock the funds they owned on the original chain. This can be
done by the project itself or Komodo can help with this process.
done by the project itself or Hush Developers can help with this process.
# Integrating DPoW Into Your Coin
@ -130,8 +110,7 @@ immediately compatible or at least a close starting point for development work.
For example, if your coin is based on Bitcoin 0.15.x, there already exists a
header file that matches that version of Bitcoin internals exactly. The GAME
coin was the first external coin to start using dPoW and [this commit](https://github.com/gamecredits-project/GameCredits/commit/e65fe302111408c02d2bf7e286205d4273fa0fed)
shows how they integrated. This was first created by the author of Komodo,
jl777, and then the author of this document ported that header file to Bitcoin
shows how they integrated. This was first created by James Lee and then the author of this document ported that header file to Bitcoin
0.11.x internals, which Zcash and all Zcash forks have as their internals. So
