Groestlcoin 22nd December Release

As per usual the 3 months has been all hand-on-deck, helping to bring further adoption utilities to Groestlcoin. The markets have been red but as always that doesn’t stop the show from going on with regards to the development since the last release update on 24th September. Here’s a recap of what has happened so far:


  • Groestlcoin was added to Changelly. One of the leading Crypto-to-Crypto exchanges that offer some of the best rates on the market – You can also buy with a debit/credit card too and you can buy/sell Groestlcoin directly from your Coinomi wallet, from the website, and you can enable Changelly swaps on your GRSPay stores!
  • Groestlcoin was added to the JAXX Liberty wallet! One of the leading multi-crypto wallets in the stores. Safely store your GRS on Android, iOS, Mac OS X, Windows, Linux or Google Chrome. With Jaxx Liberty you are always in control of your private keys, and you can use your wallet on multiple devices. Note: This directly replaces the deprecated JS Wallet which was of a similar (but older) codebase.
  • Groestlcoin was integrated into AtomicPay – A decentralised cryptocurrency payment processor that eliminates the involvement of a third-party gateway, allowing merchants to accept payments directly from their customers, with over 2500 merchants already signed up, a public release is set for Mid-January 2019.
  • Huobi officially opened trading for Groestlcoin to Korean customers! And in addition, a giveaway of up to 10,000 GRS was held!
  • Unocoin ATMs started supporting Groestlcoin at their ATMs, granting the Indian community the ability to withdraw (For INR) and deposit Groestlcoin into their UnoDax account. Groestlcoin $GRS is available on #Unodax exchange with the following pairs: $INR, $TUSD, $BTC.
  • Groestlcoin was listed on SWFT BLOCKCHAIN, giving you more opportunities to swap your other altcoins with Groestlcoin or vice versa, quickly and securely.
  • Groestlcoin was added to One Page Exchange! Where you can buy and sell Groestlcoin quickly and easily without any form of registration!
  • CryptoWolf started accepting VISA, Mastercard and Maesto to buy cryptocurrencies from the CryptoWolf exchange in EUR or USD! Providing a new FIAT gateway to buy Groestlcoin.
  • Groestlcoin has been added to CoinZark (Formally VertPig) for fast and efficient Crypto-to-Crypto swaps at very competitive rates using exchange aggregates.
  • Groestlcoin was added to PungoWallet! Pungo wallet is built to showcase the features that anyone can achieve with blockchain technology. They have built a set of modular solutions that allow any company to build a blockchain layer to interact with traditional software.
  • Groestlcoin was added to StealthEX, offering anonymous cryptocurrency swaps with tens of other coins without disclosing any personal information. Just choose the pairs, enter your address, send your coins and receive your funds!
  • Groestlcoin joined InvestFeed, granting a company listing and blue verified badge.
  • Groestlcoin was officially added to Blockfolio Signals – For those of you that use Blockfolio, you can keep updated with all the latest news straight from the app, via the Signals icon.
  • Groestlcoin has been added to DeltaDirect – Those using Delta can now stay up-to-date with the latest Groestlcoin news, straight from your Delta portfolio tracker app.
  • Groestlcoin has been added to CoinGecko Beam – Where you can easily follow us and receive updates without searching through social media.
  • Groestlcoin is now live on BitUniverse Link! All of the latest Groestlcoin updates and news will be directly available on BItUniverse.
  • Groestlcoin was added to NovaExchange! Launched in 2016 and operating from Sweden, users can trade over 300 different digital assets.

It come to light that the new Baikal BK-G28 supported the Groestl algorithm, after great lengths of discussion, the core development team decided to not fork away from these ASICs for the near future. If you missed it, a full statement on the subject can be found here:

What’s New?

Groestlcoin on Trezor Model T

As of the latest version of the Trezor Model T firmware, Groestlcoin is now officially supported! The Trezor Model T is the next-generation cryptocurrency hardware wallet, designed to be your universal vault for all of your digital assets. Store and encrypt your coins, passwords and other digital keys with confidence. The Trezor Model T now supports over 500 cryptocurrencies.


Blockbook MainNet & TestNet Block Explorer

Blockbook is an open-source Groestlcoin blockchain explorer with complete REST and websocket APIs that can be used for writing web wallets and other apps that need more advanced blockchain queries than provided by groestlcoind RPC.

Blockbook REST API provides you with a convenient, powerful and simple way to read data from the groestlcoin network and with it, build your own services.


  • Support to broadcast transactions online. Broadcast a raw transaction in hex format over the Groestlcoin network.
  • Supports every web browser
  • API – Complete REST and Websocket API for querying blocks, transactions and addresses; and receiving live updates
  • Light – Thin data model using groestlcoind RPC interface to validate blockchain information. Fast groestlcoind blockchain synchronisation (~1hrs for the entire mainnet), using RocksDB for data storage and optionally raw groestlcoind data files processing.
  • Exhaustive – Reports on double spend attempts, outpoint confirmations, outputs spend status reports. Input and Output hyperlinks in transactions. Extended view in transactions to show advanced details.
  • Open Source, written in the Go programming language.

Blockbook is available via

Blockbook testnet:

Source code:


3rd party wallets


Edge Wallet

Groestlcoin has been added to the Edge wallet for Android and iOS. Edge wallet is secure, private and intuitive. By including support for ShapeShift, Simplex and Changelly, Edge allows you to seamlessly shift between digital currencies, anywhere with an internet connection.


  • Multi-Asset Support. Supporting Bitcoin, Ethereum, Groestlcoin and many others, you can safely hold your coins.
  • Exchange Support – Supporting Shapeshift, Simplex and Changelly enables the user to seamlessly shift between digital currencies as if you were storing your funds on an exchange.
  • In-app buying and selling, exchange your FIAT for cryptocurrency directly within the app.
  • Encrypted with a username and password. Seamless login into multiple devices.
  • Easy, secure access with PIN or fingerprint. Additionally, supporting 2FA authentication.
  • Client-side encryption – All of your data is encrypted on your device before any of your information touches the Edge servers. Being free from server-side hacks and malware means that your assets are as secure as they can be.
  • Multi-Platform – Supporting both Android and iOS.



Edge app:


CoinID Wallet – Mainnet & Testnet

We are excited to announce that Groestlcoin has been added to CoinID! With integrated cold and hot wallet support, and a host of other unique wallet features, CoinID can easily become your go-to wallet for storing Groestlcoin.


  • Integrated Cold wallet. Store your funds offline and sleep tight at night. All you need is a separate Android or iOS device.
  • Transaction Batching – A feature normally reserved for exchanges, CoinID supports transaction batching, allowing the user to group transactions into one, saving space on the blockchain and lowering your transaction fees considerably as a result.
  • Complete control – Your private keys never leaves your device. “If you don’t control your private keys, you don’t own your coins”.
  • SegWit support – Support for Segregated Witness, which means smaller transaction sizes, lower fees, and supporting all 3 address types (grs1, 3, F).
  • Hierarchical Deterministic – Use a single set of keys for multiple coins and addresses. When an address is used, a new one is generated.
  • Cross-Platform – Built with React Native for rapid development cycles and cross-platform support.


Android Testnet:


iOS Testnet:


Groestlcoin Sentinel - Windows Released

Groestlcoin Sentinel is the easiest and fastest way to track balances of your Groestlcoin addresses.


  • No private keys required at all. Sentinel uses only your public addresses to keep track of your balances.
  • Capable of holding multiple groestlcoin address with tags, address and their balances.
  • Validating each address with Base58_encoding and new Bech32 format for SegWit.
  • Using a grid view to show the list, making it easy to add/edit/remove lines at a whim.
  • Import addresses in bulk from file, or paste into the textbox (Line separated)
  • Using block explorer API services to update balances
  • USD value is easy to see from using CoinMarketCap or Chainz.CryptoId.Info APIs
  • See the total Groestlcoin amount in BTC, USD and a user-defined local currency.
  • Sentinel will automatically attempt to select your local currency, changeable in the settings.
  • Automatical refreshing of your balances at regular intervals.

You can download it using the links below.

Download the Windows Wallet (64 bit) here:

Download the Windows Wallet (32 bit) here:

Source code:


Groestlcoin BIP39 Tool 0.3.9 Update

The Groestlcoin BIP39 tool is an open-source web tool for converting BIP39 mnemonic codes to addresses and private keys. This enables the greatest security against third-party wallets potentially disappearing – You’ll still have access to your funds thanks to this tool.

What’s New

  • Added Coinomi, Ledger Client, Groestlcoinomi, Trezor, Safe T, Core, Groestlpay and Samourai to BIP32 Tab
  • Added BIP49 support
  • Add BIP38 support
  • Add CSV tab for derived addresses
  • BIP84 tab for derivation path
  • Display version number in top right corner
  • Groestlcoin ticker is now also displayed
  • Refactor method to clear old data from the display
  • BIP44 ‘purpose’ and ‘coin’ fields have been made read only
  • Tab Order is now alphabetical
  • Improve showing feedback for pending calculations
  • Show error when using XPUB with hardened addresses
  • Rename variables for clarity between BIP49 and P2WPKH Nested in P2SH
  • QR Codes use correctLevel 3 instead of 2
  • Update compile script to work across python 2 and 3
  • Add BIP49 to More Info section
  • Reword entropy text to indicate using a single source only
  • Detect and warn when entropy is filtered / discarded
  • Use new xpub/xprv prefixes for Segwit BIP49
  • Allow more rows to be generated starting from a custom index
  • BIP141 tab added for full Segwit compatibility
  • Show list of word indexes. Checksum shows in entropy details
  • Populate entropy field with hex value used from PRNG
  • QR codes with accents now work correctly by replacing jquery.qrcode with kjua
  • Allow initial number of rows to be set by the user
  • Raw entropy shows groupings with space every 11 bits for easier usage
  • Warn that entropy values should exclude checksum
  • Warn when generating low entropy mnemonics
  • Warn when overriding weak entropy with a strong mnemonic length
  • Allow XPUB to be used as root key for Segwit derivations
  • Add visual privacy safeguard. List alternative tools
  • Update bootstrap from 3.2.0 to 3.3.7 and jQuery from 2.1.1 to 3.2.1
  • GroestlcoinJS library upgraded to v3.3.2
  • General code refactoring, numerous performance improvements and bug fixes

Download the Groestlcoin BIP39 tool here:

Direct link:

Source code:


Electrum-GRS 3.2.3 Update

Electrum-GRS is a lightweight "thin client" Groestlcoin wallet Windows, MacOS and Linux based on a client-server protocol. Its main advantages over the original Groestlcoin client include support for multi-signature wallets and not requiring the download of the entire block chain.

What’s New

  • HARDWARE WALLET SUPPORT: Archos Safe-T Mini is now fully supported

Electrum + Android Version 3.2.3:

  • If a BIP39 seed extension/passphrase contained multiple consecutive whitespaces or leading/trailing whitespaces, then the derived addresses were not following spec. This has been fixed, and anyone affected should move their codes. The wizard will show a warning in this case.
  • The PRNG used has been changed
  • Fix Linux distributable, ‘typing’ was not bundled and was required for Python 3.4
  • Fix spending from Segwit multi-sig wallets involving a Trezor co-signer when using a custom derivation path.
  • Several other minor bugfixes and usability improvements.


Windows & OSX:


sudo apt-get install python3-setuptools python3-pyqt5 python3-pip python3-dev libssl-dev

sudo pip3 install groestlcoin_hash

sudo pip3 install


GitHub Source server:

Github Source server installer:

Github Source client:


Groestlcoin ivendPay Integration

ivendPay and Groestlcoin cryptocurrency have announced the start of integration.

IT company ivendPay, the developer of a universal multicurrency payment module for automatic and retail trade, intends to integrate Groestlcoin cryptocurrency — one of the oldest and the most reputable Bitcoin forks into the payment system. Groestlcoin is characterized by instant transactions with almost zero commission and is optimal for mass retail trade where micropayments are mostly used.

According to Sergey Danilov, founder and CEO of ivendPay, Groestlcoin will become the 11th cryptocurrency integrated into the payment module. The first working vending machines for the sale of coffee, snacks and souvenirs, equipped with ivendPay modules, served the visitors of the CryptoEvent RIW exhibition at VDNKh in Moscow.

ivendPay terminals are designed and patented to accept payments in electronic money, cryptocurrencies and cash when connecting the corresponding cash terminal. Payment for the purchase takes a few seconds, the choice of the payment currency occurs at the time of placing the order on the screen, the payment is made by QR-code through the cryptocurrency wallet on the smartphone.

The interest in equipping vending machines with ivendPay terminals has already been shown by the companies of Malaysia and Israel, where first test networks would be installed. ivendPay compiles a waiting list for vending networks interested in buying terminals and searches for an investor to launch industrial production. According to Sergey Danilov, the universal payment terminal ivendPay for the vending machine will cost about $500.

The founder of ivendPay has welcomed the appearance of Groestlcoin among integrated cryptocurrencies, as it is another step towards the realization of the basic idea of digital money - free and cross-border access to goods and services for everybody.