hcashd

README

Hcash

Contents

• Official Web
• Innovations
  • Novel Consensus Scheme
  • Post-Quantum Features
• Starting-Hcashd
• Using HcashWallet GUI Version
• License

Official Web

https://h.cash

Innovations

To date, existing decentralized cryptocurrencies adopt either PoW consensus scheme or hybrid consensus model of PoW and PoS. However, these systems still encounter the issue of very limited efficiency/throughput. Meanwhile, upcoming quantum computers threaten existing classical cryptography which is the foundation of blockchain security. In particular, the quantum algorithm by Shor for computing discrete logarithms breaks the ECDSA signature scheme used by almost all cryptocurrencies, such as Bitcoin, Ethereum, Decred and Monero. However, if post-quantum cryptographic schemes are equipped in these systems, the throughput of them will become worse and even unbearable.

Hcash project aims to build a secure, efficient, robust and reliable decentralized system. Highlighted features such as newly-proposed hybrid consensus scheme, post-quantum digital signature, linkability among various blockchain-based and DAG-based decentralized cryptocurrencies, smart contract mechanism and post-quantum privacy-preserving scheme will be proposed and implemented in Hcash eventually.

Novel Consensus Scheme

To deal with the performance issue, we implement a novel hybrid consensus scheme with strong robustness, high throughput as well as sufficient flexibility in Hcash. On the one hand, with a newly-proposed two-layer framework of block chain, significant improvement of the efficiency is offered without compromising the security. On the other hand, with a hybrid consensus model, both PoW and PoS miners are incentivized to take part in the consensus process, thereby enhancing the security and flexibility of the consensus scheme, and providing a mechanism that supports basic DAO for future protocol updating and project investments.

For more details, please refer to our specific report.

Post-Quantum Features

To address security issues stemming from quantum computers, we design and implement post-quantum solutions in Hcash. Our proposals achieve the following 4 features:

• Compatibility: Compatible with existing ECDSA signature solution;
• Flexibility: Support multiple post-quantum signature solutions that are thoroughly analyzed, assessed and proved by international cryptography research institutions, meanwhile their security and performance must be outstanding;
• Security: the post-quantum solution must be proved secure in theory, and side-channel attack proof in practice;
• High performance: Signing and signature verification must be fast. Most importantly, the public key and signature must be short.

Please refer to our design rationale and technical report for more information.

Starting Hcashd

Hcashd is a Hypercash full node implementation written in Go (golang).

This acts as a chain daemon for the Hypercash cryptocurrency. Hcashd maintains the entire past transactional ledger of Hypercash and allows relaying of transactions to other Hypercash nodes across the world. The installation of hcashd requires Go 1.7 or newer.

• Glide

  Glide is used to manage project dependencies and provide reproducible builds. To install:

  go get -u github.com/Masterminds/glide
  

• Build and Installation

  For a first time installation, the project and dependency sources can be obtained manually with git and glide (create directories as needed):

  git clone https://github.com/HcashOrg/hcashd $GOPATH/src/github.com/HcashOrg/hcashd
  cd $GOPATH/src/github.com/HcashOrg/hcashd
  glide install
  go install $(glide nv)
  

  To update an existing source tree, pull the latest changes and install the matching dependencies:

  cd $GOPATH/src/github.com/HcashOrg/hcashd
  git pull
  glide install
  go install $(glide nv)
  

• Start running hcash full node service to synchrnoze blocks

  hcashd
  

• Start hcash solo mining

  hcashctl setgenerate true x     # where x represents the number of CPU threads
  

• Stop hcash solo mining

  hcashctl setgenerate false
  

Using HcashWallet GUI Version

HcashWallet GUI version is a graphical wallet for Hcash. You can send and receive Hcash, purchase tickets for PoS voting, get history of all your transactions and more by GUI HcashWallet.

HcashWallet GUI version is at: https://github.com/HcashOrg/hcashwallet/releases. It could be extracted and used directly.

HcashWallet GUI version user guide is at: https://github.com/HcashOrg/hcashd/wiki. If any suggestion, please post your suggestion at https://github.com/HcashOrg/hcashd/issues or send email to hypercashcn@gmail.com. Thank you very much!

License

hcashd is licensed under the copyfree ISC License.

Documentation

Overview

hcashd is a full-node hypercash implementation written in Go.

The default options are sane for most users. This means hcashd will work 'out of the box' for most users. However, there are also a wide variety of flags that can be used to control it.

The following section provides a usage overview which enumerates the flags. An interesting point to note is that the long form of all of these options (except -C) can be specified in a configuration file that is automatically parsed when hcashd starts up. By default, the configuration file is located at ~/.hcashd/hcashd.conf on POSIX-style operating systems and %LOCALAPPDATA%\hcashd\hcashd.conf on Windows. The -C (--configfile) flag, as shown below, can be used to override this location.

Usage:

hcashd [OPTIONS]

Application Options:

-V, --version             Display version information and exit
-C, --configfile=         Path to configuration file
-b, --datadir=            Directory to store data
    --logdir=             Directory to log output.
-a, --addpeer=            Add a peer to connect with at startup
    --connect=            Connect only to the specified peers at startup
    --nolisten            Disable listening for incoming connections -- NOTE:
                          Listening is automatically disabled if the --connect
                          or --proxy options are used without also specifying
                          listen interfaces via --listen
    --listen=             Add an interface/port to listen for connections
                          (default all interfaces port: 14008, testnet: 14008)
    --maxpeers=           Max number of inbound and outbound peers (125)
    --nobanning           Disable banning of misbehaving peers
    --banduration=        How long to ban misbehaving peers.  Valid time units
                          are {s, m, h}.  Minimum 1 second (24h0m0s)
    --banthreshold=       Maximum allowed ban score before disconnecting and
                          banning misbehaving peers.
    --whitelist=          Add an IP network or IP that will not be banned.
                          (eg. 192.168.1.0/24 or ::1)
-u, --rpcuser=            Username for RPC connections
-P, --rpcpass=            Password for RPC connections
    --rpclimituser=       Username for limited RPC connections
    --rpclimitpass=       Password for limited RPC connections
    --rpclisten=          Add an interface/port to listen for RPC connections
                          (default port: 11009, testnet: 12009)
    --rpccert=            File containing the certificate file
    --rpckey=             File containing the certificate key
    --rpcmaxclients=      Max number of RPC clients for standard connections
                          (10)
    --rpcmaxwebsockets=   Max number of RPC websocket connections (25)
    --norpc               Disable built-in RPC server -- NOTE: The RPC server
                          is disabled by default if no rpcuser/rpcpass or
                          rpclimituser/rpclimitpass is specified
    --notls               Disable TLS for the RPC server -- NOTE: This is only
                          allowed if the RPC server is bound to localhost
    --nodnsseed           Disable DNS seeding for peers
    --externalip=         Add an ip to the list of local addresses we claim to
                          listen on to peers
    --proxy=              Connect via SOCKS5 proxy (eg. 127.0.0.1:9050)
    --proxyuser=          Username for proxy server
    --proxypass=          Password for proxy server
    --onion=              Connect to tor hidden services via SOCKS5 proxy
                          (eg. 127.0.0.1:9050)
    --onionuser=          Username for onion proxy server
    --onionpass=          Password for onion proxy server
    --noonion             Disable connecting to tor hidden services
    --torisolation        Enable Tor stream isolation by randomizing user
                          credentials for each connection.
    --testnet             Use the test network
    --simnet              Use the simulation test network
    --nocheckpoints       Disable built-in checkpoints.  Don't do this unless
                          you know what you're doing.
    --dbtype=             Database backend to use for the Block Chain (ffldb)
    --profile=            Enable HTTP profiling on given port -- NOTE port
                          must be between 1024 and 65536
    --cpuprofile=         Write CPU profile to the specified file
    --memprofile=         Write mem profile to the specified file
    --dumpblockchain=     Write blockchain as a gob-encoded map to the
                          specified file
    --miningtimeoffset=   Offset the mining timestamp of a block by this many
                          seconds (positive values are in the past)
-d, --debuglevel=         Logging level for all subsystems {trace, debug,
                          info, warn, error, critical} -- You may also specify
                          <subsystem>=<level>,<subsystem2>=<level>,... to set
                          the log level for individual subsystems -- Use show
                          to list available subsystems (info)
    --upnp                Use UPnP to map our listening port outside of NAT
    --minrelaytxfee=      The minimum transaction fee in HCASH/kB to be
                          considered a non-zero fee.
    --limitfreerelay=     Limit relay of transactions with no transaction fee
                          to the given amount in thousands of bytes per
                          minute (15)
    --norelaypriority     Do not require free or low-fee transactions to have
                          high priority for relaying
    --maxorphantx=        Max number of orphan transactions to keep in memory
                          (1000)
    --generate            Generate (mine) bitcoins using the CPU
    --miningaddr=         Add the specified payment address to the list of
                          addresses to use for generated blocks -- At least
                          one address is required if the generate option is
                          set
    --blockminsize=       Mininum block size in bytes to be used when creating
                          a block
    --blockmaxsize=       Maximum block size in bytes to be used when creating
                          a block (750000)
    --blockprioritysize=  Size in bytes for high-priority/low-fee transactions
                          when creating a block (50000)
    --getworkkey=         DEPRECATED -- Use the --miningaddr option instead
    --nonaggressive       Disable mining off of the parent block of the blockchain
                          if there aren't enough voters
    --nominingstatesync   Disable synchronizing the mining state with other nodes
    --allowoldvotes       Enable the addition of very old votes to the mempool

    --nopeerbloomfilters  Disable bloom filtering support.
    --sigcachemaxsize=    The maximum number of entries in the signature
                          verification cache.
    --blocksonly          Do not accept transactions from remote peers.
    --relaynonstd         Relay non-standard transactions regardless of the
                          default settings for the active network.
    --rejectnonstd        Reject non-standard transactions regardless of the
                          default settings for the active network.

Help Options:

-h, --help           Show this help message