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Credits (CRDS) v1.0.0.0

CRDS logo

Copyright (c) 2017 Credits Developers

What is Credits?

  • Coin Suffix: CRDS
  • PoW Mining Algorithm: Argon2d
  • PoW Difficulty Algorithm: DELTA
  • PoW Period: ~36 years
  • PoW Target Spacing: 128 Seconds
  • PoW Reward per Block: See Below
  • Maturity: 10 Blocks
  • PoW Blocks: ~675 per day
  • Masternode Collateral Amount: 500 CRDS
  • Masternode Min Confirmation: 16 Blocks
  • Masternode Reward: See Below
  • Total Coins: 95,000,000 (~36 Years)
  • Min TX Fee: 0.0001 CRDS

Credits uses peer-to-peer technology to operate securly with no central authority (decentralisation): managing transactions and issuing currency (CRDS) are carried out collectively by the Credits network. Credits is the name of open source software which enables the use of the currency CRDS.

Credits utilises Masternodes, Privatesend and InstantSend to provide anonymous and near instant transaction confirmations.

Credits implements Gavin Andresens signature cache optimisation from Bitcoin for significantly faster transaction validation.

Masternode/Privatesend Network Information Utilisation of InstantSend for near-instant transactions and PrivateSend for anonymous transactions.

MainNet Parameters P2P Port = 31000 RPC Port = 31050 Masternodes = 31000 Magic Bytes: 0x3f 0x42 0x55 0x61

TestNet Parameters P2P Port = 31400 RPC Port = 31450 Masternodes = 31400 Magic Bytes: 0x2f 0x32 0x15 0x40

RegTest Parameters P2P Port = 31500 RPC Port = 31550 Masternodes = 31500 Magic Bytes = 0x2f 0x32 0x15 0x3f

Rewards Structure

Years Blocks PoW Masternodes
0-1 0 - 246544 10CRDS 1CRDS
1-2 246545 - 493088 10CRDS 1CRDS
2-3 493089 - 739631 9CRDS 2CRDS
3-4 739632 - 986175 9CRDS 2CRDS
4-5 986176 - 1232719 8CRDS 3CRDS
5-6 1232720 - 1479263 8CRDS 3CRDS
6-7 1479264 - 1725806 7CRDS 4CRDS
7-8 1725807 - 1972350 7CRDS 4CRDS
8-9 1972351 - 2218894 6CRDS 5CRDS
9-10 2218895 - 2465438 6CRDS 5CRDS
10-11 2465439 - 2711981 5CRDS 6CRDS
11-12 2711982 - 2958525 5CRDS 6CRDS
12-13 2958526 - 3205069 4CRDS 7CRDS
13-14 3205070 - 3451613 4CRDS 7CRDS
14-15 3451614 - 3698156 3CRDS 8CRDS
15-16 3698156 - 3944700 3CRDS 8CRDS
16-17 3944701 - 4191244 2CRDS 9CRDS
17-18 4191245 - 4437788 2CRDS 9CRDS
18-19 4437789 - 4684331 1CRDS 10CRDS
19-20 4684332 - 4930875 1CRDS 10CRDS
20-21 4930876 - 5177419 1CRDS 10CRDS
21-22 5177420 - 5423963 1CRDS 10CRDS
22-23 5423964 - 5670506 1CRDS 10CRDS
23-24 5670507 - 5917050 1CRDS 10CRDS
24-25 5917051 - 6163594 1CRDS 10CRDS
25-26 6163595 - 6410138 1CRDS 10CRDS
26-27 6410139 - 6656681 1CRDS 10CRDS
27-28 6656682 - 6903225 1CRDS 10CRDS
28-30 6903226 - 7149769 1CRDS 10CRDS
30-31 7149770 - 7396313 1CRDS 10CRDS
31-32 7396314 - 7642856 1CRDS 10CRDS
32-33 7642857 - 7889400 1CRDS 10CRDS
33-34 7889401 - 8135944 1CRDS 10CRDS
34-35 8135945 - 8382488 1CRDS 10CRDS
35-36 8382489 - 8629031 1CRDS 10CRDS


Some notes on how to build Credits in Unix.


Always use absolute paths to configure and compile Credits and the dependencies, for example, when specifying the the path of the dependency:

../dist/configure --enable-cxx --disable-shared --with-pic --prefix=$BDB_PREFIX

Here BDB_PREFIX must absolute path - it is defined using $(pwd) which ensures the usage of the absolute path.

To Build

make install # optional

This will build credits-qt as well if the dependencies are met.


These dependencies are required:

Library Purpose Description
libssl SSL Support Secure communications
libboost Boost C++ Library
libevent Networking OS independent asynchronous networking

Optional dependencies:

Library Purpose Description
miniupnpc UPnP Support Firewall-jumping support
libdb4.8 Berkeley DB Wallet storage (only needed when wallet enabled)
qt GUI GUI toolkit (only needed when GUI enabled)
protobuf Payments in GUI Data interchange format used for payment protocol (only needed when GUI enabled)
libqrencode QR codes in GUI Optional for generating QR codes (only needed when GUI enabled)
libzmq3 ZMQ notification Optional, allows generating ZMQ notifications (requires ZMQ version >= 4.x)

For the versions used in the release, see release-process.md under Fetch and build inputs.

System requirements

C++ compilers are memory-hungry. It is recommended to have at least 3 GB of memory available when compiling Credits.

Dependency Build Instructions: Ubuntu & Debian

Build requirements:

sudo apt-get install build-essential libtool automake autotools-dev autoconf pkg-config libssl-dev libcrypto++-dev libevent-dev git

for Ubuntu 12.04 and later or Debian 7 and later libboost-all-dev has to be installed:

sudo apt-get install libboost-all-dev

db4.8 packages are available here. You can add the repository using the following command:

    sudo add-apt-repository ppa:bitcoin/bitcoin
    sudo apt-get update

Ubuntu 12.04 and later have packages for libdb5.1-dev and libdb5.1++-dev, but using these will break binary wallet compatibility, and is not recommended.

for Debian 7 (Wheezy) and later: The oldstable repository contains db4.8 packages. Add the following line to /etc/apt/sources.list, replacing [mirror] with any official debian mirror.

deb http://[mirror]/debian/ oldstable main

To enable the change run

sudo apt-get update

for other Debian & Ubuntu (with ppa):

sudo apt-get install libdb4.8-dev libdb4.8++-dev

Optional (see --with-miniupnpc and --enable-upnp-default):

sudo apt-get install libminiupnpc-dev

ZMQ dependencies (provides ZMQ API 4.x):

    sudo apt-get install libzmq3-dev

Dependencies for the GUI: Ubuntu & Debian

If you want to build Credits-Qt, make sure that the required packages for Qt development are installed. Qt 5 is necessary to build the GUI. If both Qt 4 and Qt 5 are installed, Qt 5 will be used. Pass --with-gui=qt5 to configure to choose Qt5. To build without GUI pass --without-gui.

For Qt 5 you need the following:

sudo apt-get install libqt5gui5 libqt5core5a libqt5dbus5 qttools5-dev qttools5-dev-tools libprotobuf-dev protobuf-compiler libcrypto++-dev

libqrencode (optional) can be installed with:

sudo apt-get install libqrencode-dev

Once these are installed, they will be found by configure and a credits-qt executable will be built by default.


The release is built with GCC and then "strip creditsd" to strip the debug symbols, which reduces the executable size by about 90%.


miniupnpc may be used for UPnP port mapping. It can be downloaded from here. UPnP support is compiled in and turned off by default. See the configure options for upnp behavior desired:

--without-miniupnpc      No UPnP support miniupnp not required
--disable-upnp-default   (the default) UPnP support turned off by default at runtime
--enable-upnp-default    UPnP support turned on by default at runtime

To build:

tar -xzvf miniupnpc-1.6.tar.gz
cd miniupnpc-1.6
sudo su
make install

Berkeley DB

It is recommended to use Berkeley DB 4.8. If you have to build it yourself:


# Pick some path to install BDB to, here we create a directory within the credits directory
mkdir -p $BDB_PREFIX

# Fetch the source and verify that it is not tampered with
wget 'http://download.oracle.com/berkeley-db/db-4.8.30.NC.tar.gz'
echo '12edc0df75bf9abd7f82f821795bcee50f42cb2e5f76a6a281b85732798364ef  db-4.8.30.NC.tar.gz' | sha256sum -c
# -> db-4.8.30.NC.tar.gz: OK
tar -xzvf db-4.8.30.NC.tar.gz

# Build the library and install to our prefix
cd db-4.8.30.NC/build_unix/
#  Note: Do a static build so that it can be embedded into the exectuable, instead of having to find a .so at runtime
../dist/configure --prefix=/usr/local --enable-cxx
sudo make install

# Configure Credits to use our own-built instance of BDB
./configure (other args...) LDFLAGS="-L${BDB_PREFIX}/lib/" CPPFLAGS="-I${BDB_PREFIX}/include/"

Note: You only need Berkeley DB if the wallet is enabled (see the section Disable-Wallet mode below).


If you need to build Boost yourself:

sudo su
./bjam install


To help make your Credits installation more secure by making certain attacks impossible to exploit even if a vulnerability is found, binaries are hardened by default. This can be disabled with:

Hardening Flags:

./configure --enable-hardening
./configure --disable-hardening

Hardening enables the following features:

  • Position Independent Executable Build position independent code to take advantage of Address Space Layout Randomization offered by some kernels. An attacker who is able to cause execution of code at an arbitrary memory location is thwarted if he doesn't know where anything useful is located. The stack and heap are randomly located by default but this allows the code section to be randomly located as well.

    On an Amd64 processor where a library was not compiled with -fPIC, this will cause an error such as: "relocation R_X86_64_32 against `......' can not be used when making a shared object;"

    To test that you have built PIE executable, install scanelf, part of paxutils, and use:

      scanelf -e ./creditsd

    The output should contain: TYPE ET_DYN

  • Non-executable Stack If the stack is executable then trivial stack based buffer overflow exploits are possible if vulnerable buffers are found. By default, credits should be built with a non-executable stack but if one of the libraries it uses asks for an executable stack or someone makes a mistake and uses a compiler extension which requires an executable stack, it will silently build an executable without the non-executable stack protection.

    To verify that the stack is non-executable after compiling use: scanelf -e ./creditsd

    the output should contain: STK/REL/PTL RW- R-- RW-

    The STK RW- means that the stack is readable and writeable but not executable.

Disable-wallet mode

When the intention is to run only a P2P node without a wallet, credits may be compiled in disable-wallet mode with:

./configure --disable-wallet

In this case there is no dependency on Berkeley DB 4.8.

Mining is also possible in disable-wallet mode, but only using the getblocktemplate RPC call.

AVX2 Mining Optimisations

For increased performance when mining, AVX2 optimisations can be enabled.

Prior to running the build commands:


CPU's with AVX2 support:

    Haswell processor, Q2 2013
    Haswell E processor, Q3 2014
    Broadwell processor, Q4 2014
    Broadwell E processor, Q3 2016
    Skylake processor, Q3 2015
    Kaby Lake processor, Q3 2016(ULV mobile)/Q1 2017(desktop/mobile)
    Coffee Lake processor, expected in 2017
    Cannonlake processor, expected in 2017
    Carrizo processor, Q2 2015
    Ryzen processor, Q1 2017

Example Build Command

Qt Wallet and Deamon, CLI version build:

./autogen.sh && ./configure --with-gui && make

CLI and Deamon Only Buld:

./autogen.sh && ./configure --without-gui && make