Cutcoin

Cutcoin Project unites privacy focused digital currency, private tokens and bunch of basic instruments to handle them. The coin uses Proof of Stake (PoS) consensus, and that means less electricity consumption and eco-friendliness. Cutcoin belongs to CryptoNote family and it's the first coin among others that combines exceptional privacy, PoS consensus and tokens support.

License

Cutcoin is an open source software, see the full license text here.

Copyright (c) 2018-2021 CUT coin.

Copyright (c) 2014-2017 The Monero Project.

Portions Copyright (c) 2012-2013 The Cryptonote developers.

Content

• Development resources
• Research
• Translations
• Introduction
• About this project
• Supporting the project
• Contributing
• Release staging schedule and protocol
• Compiling Cutcoin from source
  • Dependencies
• Internationalization
• Debugging

Development resources

• Web: cutcoin.org
• Forum: https://bitcointalk.org/index.php?topic=5087550.msg48784779#msg48784779
• Mail: info@cutcoin.org
• GitHub: https://github.com/cutcoin
• Documentation: https://github.com/cutcoin/documentation

Research

Cutcoin Team has a solid conviction that the further advances in CryptoNote protocol development should be based on research work. We do our own researches and utilize results that presented in respectable scientific sources. If you have great ideas of how to make CryptoNote more reliable, secure and fast please contact us info@cutcoin.org.

Introduction

CUTcoin (Concealed Untraceable Transactions) is the coin that establishes a new level of privacy and usability. Cutcoin transactions keep in secret transferred amounts of funds, untracable and unlinkable. Users don't reveal their addresses and share one-time addresses instead. PoS consensus algorithm reduces power consumption and lets block pass (on average) in more predictable periods of time. This allows to increase Transaction per Second (TPS) rate if required.

PoS algorithm don't reveal any user's data except for amount of the output that subscribes a block. The output is spent during this process in special staking transaction, this helps keep overall privacy and generate constant flow of the fresh unspent outputs.

CryptoNote Tokens (CNT-1) implemented in Cutcoin is the extension of CryptoNote protocol that allows creating and manipulating named tokens. Tokens are very similar to the coin itself, and that's one of their advantages: well known and time proved protocol that guarantees reliable privacy and security. The only place where the information about tokens is stored is the Cutcoin blockchain, and this means no additional centralization were brought.

CNT-1 is extremely exciting as provides first known realization of private tokens. Tokens can be created, owned or transferred via common Cutcoin transaction. This give them all privacy features intrinsic to Cutcoin itself.

Contributing

If you want to help out, see CONTRIBUTING for a set of guidelines. Our community's help is appreciated much and the most active members become official Cutcoin Ambassadors, that gives different benefits.

Compiling Cutcoin from source

Dependencies

The following table summarizes the tools and libraries required to build the sources. A few of the libraries are also included in this repository (marked as "Vendored"). By default, the build uses the library installed on the system, and ignores the vendored sources. However, if no library is found installed on the system, then the vendored source will be built and used. The vendored sources are also used for statically-linked builds because distribution packages often include only shared library binaries (.so) but not static library archives (.a).

Dep	Min. version	Vendored	Debian/Ubuntu pkg	Arch pkg	Fedora	Optional	Purpose
GCC	4.7.3	NO	build-essential	base-devel	gcc	NO
CMake	3.5	NO	cmake	cmake	cmake	NO
pkg-config	any	NO	pkg-config	base-devel	pkgconf	NO
Boost	1.58	NO	libboost-all-dev	boost	boost-devel	NO	C++ libraries
OpenSSL	basically any	NO	libssl-dev	openssl	openssl-devel	NO	sha256 sum
libzmq	3.0.0	NO	libzmq3-dev	zeromq	cppzmq-devel	NO	ZeroMQ library
OpenPGM	?	NO	libpgm-dev	libpgm	openpgm-devel	NO	For ZeroMQ
libunbound	1.4.16	YES	libunbound-dev	unbound	unbound-devel	NO	DNS resolver
libsodium	?	NO	libsodium-dev	libsodium	libsodium-devel	NO	cryptography
libunwind	any	NO	libunwind8-dev	libunwind	libunwind-devel	YES	Stack traces
liblzma	any	NO	liblzma-dev	xz	xz-devel	YES	For libunwind
libreadline	6.3.0	NO	libreadline6-dev	readline	readline-devel	YES	Input editing
ldns	1.6.17	NO	libldns-dev	ldns	ldns-devel	YES	SSL toolkit
expat	1.1	NO	libexpat1-dev	expat	expat-devel	YES	XML parsing
GTest	1.5	YES	libgtest-dev^	gtest	gtest-devel	YES	Test suite
Doxygen	any	NO	doxygen	doxygen	doxygen	YES	Documentation
Graphviz	any	NO	graphviz	graphviz	graphviz	YES	Documentation

[^] On Debian/Ubuntu libgtest-dev only includes sources and headers. You must build the library binary manually. This can be done with the following command

sudo apt-get install libgtest-dev && cd /usr/src/gtest && sudo cmake . && sudo make && sudo mv libg* /usr/lib/

Debian / Ubuntu one liner for all dependencies

sudo apt update && sudo apt install git build-essential cmake pkg-config libboost-all-dev libssl-dev libzmq3-dev libunbound-dev libsodium-dev libunwind8-dev liblzma-dev libreadline6-dev libldns-dev libexpat1-dev doxygen graphviz libpgm-dev

Install all dependencies at once on macOS with the provided Brewfile: brew update && brew bundle --file=contrib/brew/Brewfile

FreeBSD one liner for required to build dependencies pkg install git gmake cmake pkgconf boost-libs cppzmq libsodium

Debug mode build also requires QT4, on Debian / Ubuntu

sudo apt install qt4-default

Cloning the repository

Clone recursively to pull-in needed submodule(s):

$ git clone --recursive https://github.com/cutcoin/cutcoin

If you already have a repo cloned, initialize and update:

$ cd cutcoin && git submodule init && git submodule update

Build instructions

Cutcoin uses the CMake build system and a top-level Makefile that invokes cmake commands as needed.

On Linux and OS X

• Install the dependencies

• Change to the root of the source code directory, change to the most recent release branch, and build:

    cd cutcoin
    git checkout master
    make
  

  Optional: If your machine has several cores and enough memory, enable parallel build by running make -j<number of threads> instead of make. For this to be worthwhile, the machine should have one core and about 2GB of RAM available per thread.

  Note: If cmake can not find zmq.hpp file on OS X, installing zmq.hpp from https://github.com/zeromq/cppzmq to /usr/local/include should fix that error.

• The resulting executables can be found in build/release/bin

• Add PATH="$PATH:$HOME/cutcoin/build/release/bin" to .profile

• Run Cutcoin with cutcoind --detach

• Optional: build and run the test suite to verify the binaries:

    make release-test
  

  NOTE: core_tests test may take a few hours to complete.

• Optional: to build binaries suitable for debugging:

     make debug
  

• Optional: to build statically-linked binaries:

     make release-static
  

Dependencies need to be built with -fPIC. Static libraries usually aren't, so you may have to build them yourself with -fPIC. Refer to their documentation for how to build them.

• Optional: build documentation in doc/html (omit HAVE_DOT=YES if graphviz is not installed):

    HAVE_DOT=YES doxygen Doxyfile
  

On Windows:

Binaries for Windows are built on Windows using the MinGW toolchain within MSYS2 environment. The MSYS2 environment emulates a POSIX system. The toolchain runs within the environment and cross-compiles binaries that can run outside of the environment as a regular Windows application.

Preparing the build environment

• Download and install the MSYS2 installer, either the 64-bit or the 32-bit package, depending on your system.

• Open the MSYS shell via the MSYS2 Shell shortcut

• Update packages using pacman:

  pacman -Syu

• Exit the MSYS shell using Alt+F4

• Edit the properties for the MSYS2 Shell shortcut changing "msys2_shell.bat" to "msys2_shell.cmd -mingw64" for 64-bit builds or "msys2_shell.cmd -mingw32" for 32-bit builds

• Restart MSYS shell via modified shortcut and update packages again using pacman:

  pacman -Syu

• Install dependencies:

  To build for 64-bit Windows:

  pacman -S mingw-w64-x86_64-toolchain make mingw-w64-x86_64-cmake mingw-w64-x86_64-boost mingw-w64-x86_64-openssl mingw-w64-x86_64-zeromq mingw-w64-x86_64-libsodium mingw-w64-x86_64-hidapi git

  To build for 32-bit Windows:

  pacman -S mingw-w64-i686-toolchain make mingw-w64-i686-cmake mingw-w64-i686-boost mingw-w64-i686-openssl mingw-w64-i686-zeromq mingw-w64-i686-libsodium mingw-w64-i686-hidapi git

• Open the MingW shell via MinGW-w64-Win64 Shell shortcut on 64-bit Windows or MinGW-w64-Win64 Shell shortcut on 32-bit Windows. Note that if you are running 64-bit Windows, you will have both 64-bit and 32-bit MinGW shells.

Cloning

• To git clone, run:

  git clone --recursive https://github.com/cutcoin/cutcoin.git

Building

• Change to the cloned directory, run:

  cd cutcoin

• If you are on a 64-bit system, run:

  make release-static-win64

• If you are on a 32-bit system, run:

  make release-static-win32

• The resulting executables can be found in build/release/bin

• Optional: to build Windows binaries suitable for debugging on a 64-bit system, run:

  make debug-static-win64

• Optional: to build Windows binaries suitable for debugging on a 32-bit system, run:

  make debug-static-win32

• The resulting executables can be found in build/debug/bin

Running the daemon (cutcoind)

The build places the binary in bin/ sub-directory within the build directory from which cmake was invoked (repository root by default). To run in foreground:

./bin/cutcoind

To list all available options, run ./bin/cutcoind --help. Options can be specified either on the command line or in a configuration file passed by the --config-file argument. To specify an option in the configuration file, add a line with the syntax argumentname=value, where argumentname is the name of the argument without the leading dashes, for example log-level=1.

To run in background:

./bin/cutcoind --log-file cutcoind.log --detach

To run as a systemd service, copy cutcoind.service to /etc/systemd/system/ and cutcoind.conf to /etc/. The example service assumes that the user cutcoin exists and its home is the data directory specified in the example config.

If you're on Mac, you may need to add the --max-concurrency 1 option to cutcoin-wallet-cli, and possibly cutcoind, if you get crashes refreshing.

Internationalization

See README.i18n.md.

Using Tor

While CUT coin isn't made to integrate with Tor, it can be used wrapped with torsocks, by setting the following configuration parameters and environment variables:

• --p2p-bind-ip 127.0.0.1 on the command line or p2p-bind-ip=127.0.0.1 in cutcoind.conf to disable listening for connections on external interfaces.
• --no-igd on the command line or no-igd=1 in cutcoind.conf to disable IGD (UPnP port forwarding negotiation), which is pointless with Tor.
• DNS_PUBLIC=tcp or DNS_PUBLIC=tcp://x.x.x.x where x.x.x.x is the IP of the desired DNS server, for DNS requests to go over TCP, so that they are routed through Tor. When IP is not specified, cutcoind uses the default list of servers defined in src/common/dns_utils.cpp.
• TORSOCKS_ALLOW_INBOUND=1 to tell torsocks to allow cutcoind to bind to interfaces to accept connections from the wallet. On some Linux systems, torsocks allows binding to localhost by default, so setting this variable is only necessary to allow binding to local LAN/VPN interfaces to allow wallets to connect from remote hosts. On other systems, it may be needed for local wallets as well.
• Do NOT pass --detach when running through torsocks with systemd, (see utils/systemd/cutcoind.service for details).
• If you use the wallet with a Tor daemon via the loopback IP (eg, 127.0.0.1:9050), then use --untrusted-daemon unless it is your own hidden service.

Example command line to start cutcoind through Tor:

DNS_PUBLIC=tcp torsocks cutcoind --p2p-bind-ip 127.0.0.1 --no-igd

Using Tor on Tails

TAILS ships with a very restrictive set of firewall rules. Therefore, you need to add a rule to allow this connection too, in addition to telling torsocks to allow inbound connections. Full example:

sudo iptables -I OUTPUT 2 -p tcp -d 127.0.0.1 -m tcp --dport 18081 -j ACCEPT
DNS_PUBLIC=tcp torsocks ./cutcoind --p2p-bind-ip 127.0.0.1 --no-igd --rpc-bind-ip 127.0.0.1 \
    --data-dir /home/amnesia/Persistent/your/directory/to/the/blockchain

Debugging

This section contains general instructions for debugging failed installs or problems encountered with CUT coin. First ensure you are running the latest version built from the Github repo.

Obtaining stack traces and core dumps on Unix systems

We generally use the tool gdb (GNU debugger) to provide stack trace functionality, and ulimit to provide core dumps in builds which crash or segfault.

• To use gdb in order to obtain a stack trace for a build that has stalled:

Run the build.

Once it stalls, enter the following command:

gdb /path/to/cutcoind `pidof cutcoind` 

Type thread apply all bt within gdb in order to obtain the stack trace

• If however the core dumps or segfaults:

Enter ulimit -c unlimited on the command line to enable unlimited filesizes for core dumps

Enter echo core | sudo tee /proc/sys/kernel/core_pattern to stop cores from being hijacked by other tools

Run the build.

When it terminates with an output along the lines of "Segmentation fault (core dumped)", there should be a core dump file in the same directory as cutcoind. It may be named just core, or core.xxxx with numbers appended.

You can now analyse this core dump with gdb as follows:

gdb /path/to/cutcoind /path/to/dumpfile

Print the stack trace with bt

• To run cutcoin within gdb:

Type gdb /path/to/cutcoind

Pass command-line options with --args followed by the relevant arguments

Type run to run cutcoind

Analysing memory corruption

There are two tools available:

• ASAN

Configure CUT coin with the -D SANITIZE=ON cmake flag, eg:

cd build/debug && cmake -D SANITIZE=ON -D CMAKE_BUILD_TYPE=Debug ../..

You can then run the cutcoin tools normally. Performance will typically halve.

• valgrind

Install valgrind and run as valgrind /path/to/cutcoind. It will be very slow.

LMDB

Instructions for debugging suspected blockchain corruption as per @HYC

There is an mdb_stat command in the LMDB source that can print statistics about the database but it's not routinely built. This can be built with the following command:

cd ~/cutcoin/external/db_drivers/liblmdb && make

The output of mdb_stat -ea <path to blockchain dir> will indicate inconsistencies in the blocks, block_heights and block_info table.

The output of mdb_dump -s blocks <path to blockchain dir> and mdb_dump -s block_info <path to blockchain dir> is useful for indicating whether blocks and block_info contain the same keys.

These records are dumped as hex data, where the first line is the key and the second line is the data.