BIP38 Treasure Hunt : Bitcoin

Groestlcoin 6th Anniversary Release

Introduction

Dear Groestlers, it goes without saying that 2020 has been a difficult time for millions of people worldwide. The groestlcoin team would like to take this opportunity to wish everyone our best to everyone coping with the direct and indirect effects of COVID-19. Let it bring out the best in us all and show that collectively, we can conquer anything.
The centralised banks and our national governments are facing unprecedented times with interest rates worldwide dropping to record lows in places. Rest assured that this can only strengthen the fundamentals of all decentralised cryptocurrencies and the vision that was seeded with Satoshi's Bitcoin whitepaper over 10 years ago. Despite everything that has been thrown at us this year, the show must go on and the team will still progress and advance to continue the momentum that we have developed over the past 6 years.
In addition to this, we'd like to remind you all that this is Groestlcoin's 6th Birthday release! In terms of price there have been some crazy highs and lows over the years (with highs of around $2.60 and lows of $0.000077!), but in terms of value– Groestlcoin just keeps getting more valuable! In these uncertain times, one thing remains clear – Groestlcoin will keep going and keep innovating regardless. On with what has been worked on and completed over the past few months.

UPDATED - Groestlcoin Core 2.18.2

This is a major release of Groestlcoin Core with many protocol level improvements and code optimizations, featuring the technical equivalent of Bitcoin v0.18.2 but with Groestlcoin-specific patches. On a general level, most of what is new is a new 'Groestlcoin-wallet' tool which is now distributed alongside Groestlcoin Core's other executables.
NOTE: The 'Account' API has been removed from this version which was typically used in some tip bots. Please ensure you check the release notes from 2.17.2 for details on replacing this functionality.

How to Upgrade?

Windows
If you are running an older version, shut it down. Wait until it has completely shut down (which might take a few minutes for older versions), then run the installer.
OSX
If you are running an older version, shut it down. Wait until it has completely shut down (which might take a few minutes for older versions), run the dmg and drag Groestlcoin Core to Applications.
Ubuntu
http://groestlcoin.org/forum/index.php?topic=441.0

Other Linux

http://groestlcoin.org/forum/index.php?topic=97.0

Download

Download the Windows Installer (64 bit) here
Download the Windows Installer (32 bit) here
Download the Windows binaries (64 bit) here
Download the Windows binaries (32 bit) here
Download the OSX Installer here
Download the OSX binaries here
Download the Linux binaries (64 bit) here
Download the Linux binaries (32 bit) here
Download the ARM Linux binaries (64 bit) here
Download the ARM Linux binaries (32 bit) here

Source

ALL NEW - Groestlcoin Moonshine iOS/Android Wallet

Built with React Native, Moonshine utilizes Electrum-GRS's JSON-RPC methods to interact with the Groestlcoin network.
GRS Moonshine's intended use is as a hot wallet. Meaning, your keys are only as safe as the device you install this wallet on. As with any hot wallet, please ensure that you keep only a small, responsible amount of Groestlcoin on it at any given time.

Features

Download

iOS
Android

Source

ALL NEW! – HODL GRS Android Wallet

HODL GRS connects directly to the Groestlcoin network using SPV mode and doesn't rely on servers that can be hacked or disabled.
HODL GRS utilizes AES hardware encryption, app sandboxing, and the latest security features to protect users from malware, browser security holes, and even physical theft. Private keys are stored only in the secure enclave of the user's phone, inaccessible to anyone other than the user.
Simplicity and ease-of-use is the core design principle of HODL GRS. A simple recovery phrase (which we call a Backup Recovery Key) is all that is needed to restore the user's wallet if they ever lose or replace their device. HODL GRS is deterministic, which means the user's balance and transaction history can be recovered just from the backup recovery key.

Features

Download

Main Release (Main Net)
Testnet Release

Source

ALL NEW! – GroestlcoinSeed Savior

Groestlcoin Seed Savior is a tool for recovering BIP39 seed phrases.
This tool is meant to help users with recovering a slightly incorrect Groestlcoin mnemonic phrase (AKA backup or seed). You can enter an existing BIP39 mnemonic and get derived addresses in various formats.
To find out if one of the suggested addresses is the right one, you can click on the suggested address to check the address' transaction history on a block explorer.

Features

Live Version (Not Recommended)

https://www.groestlcoin.org/recovery/

Download

https://github.com/Groestlcoin/mnemonic-recovery/archive/master.zip

Source

ALL NEW! – Vanity Search Vanity Address Generator

NOTE: NVidia GPU or any CPU only. AMD graphics cards will not work with this address generator.
VanitySearch is a command-line Segwit-capable vanity Groestlcoin address generator. Add unique flair when you tell people to send Groestlcoin. Alternatively, VanitySearch can be used to generate random addresses offline.
If you're tired of the random, cryptic addresses generated by regular groestlcoin clients, then VanitySearch is the right choice for you to create a more personalized address.
VanitySearch is a groestlcoin address prefix finder. If you want to generate safe private keys, use the -s option to enter your passphrase which will be used for generating a base key as for BIP38 standard (VanitySearch.exe -s "My PassPhrase" FXPref). You can also use VanitySearch.exe -ps "My PassPhrase" which will add a crypto secure seed to your passphrase.
VanitySearch may not compute a good grid size for your GPU, so try different values using -g option in order to get the best performances. If you want to use GPUs and CPUs together, you may have best performances by keeping one CPU core for handling GPU(s)/CPU exchanges (use -t option to set the number of CPU threads).

Features

Usage

https://github.com/Groestlcoin/VanitySearch#usage

Download

Source

ALL NEW! – Groestlcoin EasyVanity 2020

Groestlcoin EasyVanity 2020 is a windows app built from the ground-up and makes it easier than ever before to create your very own bespoke bech32 address(es) when whilst not connected to the internet.
If you're tired of the random, cryptic bech32 addresses generated by regular Groestlcoin clients, then Groestlcoin EasyVanity2020 is the right choice for you to create a more personalised bech32 address. This 2020 version uses the new VanitySearch to generate not only legacy addresses (F prefix) but also Bech32 addresses (grs1 prefix).

Features

Download

Source

Remastered! – Groestlcoin WPF Desktop Wallet (v2.19.0.18)

Groestlcoin WPF is an alternative full node client with optional lightweight 'thin-client' mode based on WPF. Windows Presentation Foundation (WPF) is one of Microsoft's latest approaches to a GUI framework, used with the .NET framework. Its main advantages over the original Groestlcoin client include support for exporting blockchain.dat and including a lite wallet mode.
This wallet was previously deprecated but has been brought back to life with modern standards.

Features

Remastered Improvements

Download

Source

ALL NEW! – BIP39 Key Tool

Groestlcoin BIP39 Key Tool is a GUI interface for generating Groestlcoin public and private keys. It is a standalone tool which can be used offline.

Features

Download

Windows
Linux :
 pip3 install -r requirements.txt python3 bip39\_gui.py 

Source

ALL NEW! – Electrum Personal Server

Groestlcoin Electrum Personal Server aims to make using Electrum Groestlcoin wallet more secure and more private. It makes it easy to connect your Electrum-GRS wallet to your own full node.
It is an implementation of the Electrum-grs server protocol which fulfils the specific need of using the Electrum-grs wallet backed by a full node, but without the heavyweight server backend, for a single user. It allows the user to benefit from all Groestlcoin Core's resource-saving features like pruning, blocks only and disabled txindex. All Electrum-GRS's feature-richness like hardware wallet integration, multi-signature wallets, offline signing, seed recovery phrases, coin control and so on can still be used, but connected only to the user's own full node.
Full node wallets are important in Groestlcoin because they are a big part of what makes the system be trust-less. No longer do people have to trust a financial institution like a bank or PayPal, they can run software on their own computers. If Groestlcoin is digital gold, then a full node wallet is your own personal goldsmith who checks for you that received payments are genuine.
Full node wallets are also important for privacy. Using Electrum-GRS under default configuration requires it to send (hashes of) all your Groestlcoin addresses to some server. That server can then easily spy on your transactions. Full node wallets like Groestlcoin Electrum Personal Server would download the entire blockchain and scan it for the user's own addresses, and therefore don't reveal to anyone else which Groestlcoin addresses they are interested in.
Groestlcoin Electrum Personal Server can also broadcast transactions through Tor which improves privacy by resisting traffic analysis for broadcasted transactions which can link the IP address of the user to the transaction. If enabled this would happen transparently whenever the user simply clicks "Send" on a transaction in Electrum-grs wallet.
Note: Currently Groestlcoin Electrum Personal Server can only accept one connection at a time.

Features

Download

Windows
Linux / OSX (Instructions)

Source

UPDATED – Android Wallet 7.38.1 - Main Net + Test Net

The app allows you to send and receive Groestlcoin on your device using QR codes and URI links.
When using this app, please back up your wallet and email them to yourself! This will save your wallet in a password protected file. Then your coins can be retrieved even if you lose your phone.

Changes

Download

Main Net
Main Net (FDroid)
Test Net

Source

UPDATED – Groestlcoin Sentinel 3.5.06 (Android)

Groestlcoin Sentinel is a great solution for anyone who wants the convenience and utility of a hot wallet for receiving payments directly into their cold storage (or hardware wallets).
Sentinel accepts XPUB's, YPUB'S, ZPUB's and individual Groestlcoin address. Once added you will be able to view balances, view transactions, and (in the case of XPUB's, YPUB's and ZPUB's) deterministically generate addresses for that wallet.
Groestlcoin Sentinel is a fork of Groestlcoin Samourai Wallet with all spending and transaction building code removed.

Changes

Download

Source

UPDATED – P2Pool Test Net

Changes

Download

Pre-Hosted Testnet P2Pool is available via http://testp2pool.groestlcoin.org:21330/static/

Source

submitted by Yokomoko_Saleen to groestlcoin [link] [comments]

Groestlcoin September 2019 Development Release/Update!

For a more interactive view of changes, click here
In our current world; bordering on financial chaos, with tariff wars, Brexit and hyperinflation rife, you can count on Groestlcoin to consistently produce innovation that strikes to take the power away from the few and into the many, even after a full five and a half years of solid development.
Here is what the team has already announced in the last 3 months since the last development update:

What's Being Released Today?

Groestl Nodes

What am I?

Groestl Nodes aims to map out and compare the status of the Groestlcoin mainnet and testnet networks. Even though these networks share the same protocol, there is currently no way to directly compare these coins in a single location. These statistics are essential to evaluate the relative health of both networks.

Features

Source - Website

Groestlcoin Transaction Tool

What am I?

This is a tool for creating unsigned raw Groestlcoin transactions and also to verify existing transactions by entering in the transaction hex and converting this to a human-readable format to verify that a transaction is correct before it is signed.

Features

SourceDownload

Groestlcoin AGCore

What am I?

AGCore is an Android app designed to make it easier to run a Groestlcoin Core node on always-on Android appliances such as set-top boxes, Android TVs and repurposed tablets/phones. If you are a non-technical user of Groestlcoin and want an Android app that makes it easy to run a Groestlcoin Core node by acting as a wrapper, then AG Core is the right choice for you.

What's Changed?

Source - Download

Groestlcoin Electrum

What's Changed?

Android Electrum-Specific

OSXWindowsWindows StandaloneWindows PortableLinux - Android
Server SourceServer Installer SourceClient SourceIcon SourceLocale Source

Android Wallet – Including Android Wallet Testnet

What am I?

Android Wallet is a BIP-0032 compatible hierarchial deterministic Groestlcoin Wallet, allowing you to send and receive Groestlcoin via QR codes and URI links.

V7.11.1 Changes

Groestlcoin Java Library SourceSource - DownloadTestnet Download

Groestlwallet

What am I?

Groestlwallet is designed to protect you from malware, browser security holes, even physical theft. With AES hardware encryption, app sandboxing, keychain and code signatures, groestlwallet represents a significant security advance over web and desktop wallets, and other mobile platforms.
Simplicity is groestlwallet's core design principle. Because groestlwallet is "deterministic", your balance and entire transaction history can be restored from just your recovery phrase.

iOS 0.7.3 Changes

Android v89 Changes

iOS SourceAndroid Source - Android DownloadiOS Download

Groestlcoinomi Released

What am I?

Groestlcoinomi is a lightweight thin-client Groestlcoin wallet based on a client-server protocol.

Groestlcoinomi v1.1 Desktop Changes

Groestlcoinomi Android v1.6 Changes

Groestlcoin Java Library SourceAndroid Source
Android DownloadWindows DownloadMac OS DownloadLinux Download

Groestlcoin BIP39 Tool

What's Changed?

Source - Download
submitted by Yokomoko_Saleen to groestlcoin [link] [comments]

Agreement idea with a local Fast food restaurant to accept donated BCH paper wallet to feed the poor

I have this idea of giving few poor people a paper wallet that hold about 2-5 USD and referring them to a nearby affiliated restaurant that accept Bitcoin Cash. They can get a decent meal there and that will help with adoption and I'll know that my money went to feed a poor person.

That sounded real easy but it's not. I probably will have to deposit a sum of money in that restaurant and agree with them to load those paper wallets and send the money back to me while deducting the meal value from my deposit.

The Bitcoin Cash Register (BCH) App will work with people who have smart phones but may not work with poor people. hope it will be able to load a paper wallet and send it to specific address in the future using the app. It will makes this idea much more easier. It's like smart and open coupon system.

Why donations? well, the idea started when I was looking for a way for people who receive tips to spend their BCH and know that it really worth something. If I go to a restaurant and tell them I'll install a new payment method they may question my intention but if you combine a small donation with good cause I think they will be more open to try it.

I want your opinion on this, what are your suggestions. How to make this work with the current available tools?

UPDATE: What is needed is an application that Sweep the private key printed and send it to a stored address I own. Similar to the way Bitcoin Cash Register (BCH) App but it should be able to sweep the private key and forward the balance to my address.

UPDATE 2: With BIP38 password-encrypted paper wallet is it also possible to lock funds to be spent only with merchants that have the password.
submitted by Damascene_U to btc [link] [comments]

BIP38 Treasure Hunt

I've been thinking of putting together a bitcoin treasure hunt. It would start with the release of a BIP38 encrypted private key and a series of clues that each reveal parts of the encryption password. But I'm not sure how secure BIP38 would be to a determined cracker. So, I'm posting an encrypted private key here and inviting anyone interested to try and crack it. I'll post hints to the password periodically to determine at what point it can be cracked.
public key: 1L9hnNFEBpKLBdasKfxGrEjpxiMiaBWjVF
private key: 6PnQ6CqY5Pu4CiXEFh1fqomhBQadTdnVpr4mu25RN8kQkVPaNSa3NprBYh
Wallet value is .01 BTC, approx value $64.
The password is a series of 6 random words followed by a single digit. The words are all lower case and have no separator.
Hint 1: One of the words is: "bounded"
Hint 2: Other words include "piggy", "fife", and "saddles"
Hint 3: Another word: "malta"
Bonus Hint: The remaining hidden word is 6 letters long
submitted by mrxsdcuqr7x284k6 to Bitcoin [link] [comments]

Summary: pitfalls of paper wallets

Pitfalls and solutions of paper wallets

Creating paper wallets:

Problematic action: Create a paper wallet on a paper wallet service website without disconnecting from the internet. Reason: It's extremely insecure for many reasons, some being 1) the website is hacked with generated private keys sent to the hacker; 2) there may be malware in the browser or in the operating system that sends the private keys to the hacker. Solution: The bottom line is to disconnect the internet before creating the paper wallet. It's not secure enough because 1) the malware can save the private keys and wait for internet connection to send them out; 2) the malware can interfere with the generation process itself and give you a private key that is already known to the hacker, which is called backdooring the random number generator; 3) the private keys may exist on the hard disk therefore may be extracted by malware or after the computer is disposed. Better solution: Download the paper wallet app from an online computer. Copy it to an offline computer via a flash drive. Run it from there. Best solution: Use a live operating system, such as a Linux live CD, to run the paper wallet app. This is not ultimately bullet-proof, especially for high-value targets, because there exist malware that can hide in the BIOS and firmware of your computer and can infect your live operating system. It should be secure enough for average Joes.
Problematic action: Create a paper wallet without serious verifications. Reason: There may be incompatible issues with operating systems and browsers. Solution: Run tests on various operating systems and various browsers before putting BTC in. Make sure the generated private keys are identical. This applies to regular paper wallets and BIP38 paper wallets. Make sure the decrypted BIP38 keys are correct.
Problematic action: Create a brain wallet created by bitaddress.org or other brain wallets without key stretching. Reason: It has been proven insecure. Solution: Use WarpWallet or other brain wallets with key stretching, e.g., scrypt, bcrypt, sha512crypt, pbkdf2, and so on.

Printing paper wallets:

Problematic action: Use a wireless printer. Reason: It's insecure because wireless networks are insecure. Solution: Use a wired printer.
Problematic action: Use an advanced printer, which has internal storage, such as a hard drive. Reason: It is insecure because the private key of the paper wallet printed may be stored on the internal storage, therefore may be recovered if the printer is sold or scrapped. Solution: Use a dumb printer. Or keep the printer locked up and never sell or scrap it. Or smash the printer, including and especially the internal storage.
Problematic action: Leave the printer open for other people to access after printing without turning it off. Reason: It's insecure because the private key printed may still be in the memory of the printer. Solution: Turn the printer off after printing.
Problematic action: Leave the computer untreated after printing. Reason: It's insecure because the printer driver and/or operating system may be keeping copies of the documents you print in some sort of "spool" or print queue. Solution: Use a live operating system, such as a Linux live CD, to print.
Problematic action: Use a shared printer (at work or school, for example). Reason: It's insecure because 1) the printer may have a glitch and someone else may get your printouts; 2) the printing jobs may be centrally logged. Solution: Don't. Use your own printer.
Problematic action: Use a printer to print the private key or the QR code of the private key. Reason: See above. Solution 1: Don't use a printer for private key stuff. Hand-write the private key. Hand-draw the QR code if you and the helping checker are patient enough. Or ignore the QR code since hand-drawing the QR code of the private key may be too time-consuming. Double check. Then check it again, preferably on a different day. Get someone you trust to check it. Then get him/her to check it again, preferably on a different day. (Testing the private key in a wallet app can make it sure. But it comes with risks.) Solution 2: Don't use a printer for private key stuff. Use brain wallet. Write down the passphrase and the relevant information, e.g., the name of the tool used, e.g., WarpWallet, and the instructions. Store it the same way as a paper wallet. Save and store some copies of the tool, in case the future versions become incompatible. (There are pitfalls for creating man-made passphrases. It is beyond the scope of this post. In a nutshell, don't create the passphrase (solely) with your brain, and don't keep the passphrase (solely) with your brain.)

Spending from paper wallets:

Problematic action: Import a paper wallet private key into a wallet app, then spend directly from the paper wallet address.
Mistake: Expect the paper wallet automatically receives/holds changes, similar to a real-life wallet, which may not be the case. Reason: Early wallet apps didn't handle the changes correctly. The changes became the transaction fees of the miners. There is a misunderstanding of how Bitcoin works. There is no account balance of any kind in Bitcoin. There is only Unspent Transaction Outputs (UTXOs). The receiving addresses of changes, which will become the new UTXOs, must be specified when BTC is spent. Otherwise, the changes will automatically become the transaction fees. This depends on the implementation of the wallet app, which should not be trusted.
Mistake: Think nothing is wrong if changes are handled correctly. Reason: It's called address reuse, which is not recommended in Bitcoin because 1) it reduces anonymity of both the sender and all the consecutive receivers; 2) it reduces the security by exposing the public key, which is vulnerable to quantum computing. Addresses are hashes of public keys, which are safe from quantum computing.
Mistake: Destroy the paper wallet after it's imported into an HD wallet, thinking that it has become a part of the HD wallet and it's safe to destroy because the master seed of the HD has been backed up. Reason: It is not a part of the HD wallet. If the paper wallet (the paper) is destroyed and the app is uninstalled, the BTC is gone even if the HD wallet is recovered from its master seed.
The right way: Spend (transact) all BTC in a paper wallet to an address of your wallet app. It is called "sweeping", which is completely different from importing the private key. Spend BTC from there. After all the spending is finished, create a new paper wallet and transact all the remaining BTC to it. Store the new paper wallet. Keep the old one for future reference, or destroy it if you don't want the trace.

Destroying paper wallets:

Problematic action: Destroy a paper wallet after it is used. Reason: You may need to prove you had control of that address some day, e.g., for taxation purpose. In the case of a chain split, you may have a balance on the other chain. Solution: Don't ever destroy a paper wallet. Keep it on file. Mark it with the relevant information, e.g., "Used in April 2017". Unless you don't want to be tied to the address.

Pitfalls not specific to but more likely happen to paper wallets:

Problematic action: Google a famous wallet app, click the first link or the sponsored link, download/install it, and use it, without serious research. Reason: It's insecure because the wallet app may be a scam. Solution: Do thorough research prior to deciding which wallet app to use. Find the official site prior to downloading/installing it.
Additions and corrections are welcome.
Edit: multiple editing for additions, corrections, and clarifications.
Disclaimer: Although I set off to make this article in order to use paper wallet safely, I ended up not using it. Some of the solutions are collected from the internet. Some are my untested ideas. Use the article at your risk.
submitted by exab to Bitcoin [link] [comments]

Groestlcoin Christmas Release!

Groestlcoin Dec 2018 Christmas Release Update

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:

Recap:

What’s New Today?

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.

Features:

Blockbook is available via https://blockbook.groestlcoin.org/ Testnet: https://blockbook-test.groestlcoin.org/ Source code: https://github.com/Groestlcoin/blockbook

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.

Features:

Android: https://play.google.com/store/apps/details?id=co.edgesecure.app
iOS: https://itunes.apple.com/us/app/edge-bitcoin-wallet/id1344400091?mt=8
Direct Android: https://edge.app/app

CoinID Wallet

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. More details can be found here: https://coinid.org/s/groestlcoin-wallet-overview.pdf

Features

Android: https://play.google.com/store/apps/details?id=org.coinid.wallet.grs
iOS: https://itunes.apple.com/us/app/grs-wallet-for-coinid/id1439638550

Groestlcoin Sentinel - Windows Released

Groestlcoin Sentinel is the easiest and fastest way to track balances of your Groestlcoin addresses.
Features
You can download it using the links below.
Download the Windows Wallet (64 bit) here: https://github.com/Groestlcoin/Groestlcoin-Sentinel-Windows/releases/download/1.0/SentinelSetup_x64.msi
Download the Windows Wallet (32 bit) here: https://github.com/Groestlcoin/Groestlcoin-Sentinel-Windows/releases/download/1.0/SentinelSetup_x86.msi
Source code: https://github.com/Groestlcoin/Groestlcoin-Sentinel-Windows/

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
Download the Groestlcoin BIP39 tool here: https://github.com/Groestlcoin/bip39/archive/master.zip
Source code: https://github.com/groestlcoin/bip39
Or use hosted version: https://groestlcoin.org/bip39/

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

Electrum + Android Version 3.2.3:

Android: https://play.google.com/store/apps/details?id=org.groestlcoin.electrumgrs
Windows & OSX: https://github.com/Groestlcoin/electrum-grs/releases/
Linux:
sudo apt-get install python3-setuptools python3-pyqt5 python3-pip python3-dev libssl-dev sudo pip3 install groestlcoin_hash sudo pip3 install https://github.com/Groestlcoin/electrum-grs/releases/download/v3.2.3/Electrum-grs-3.2.3.tar.gz electrum-grs
GitHub Source server: https://github.com/Groestlcoin/electrumx-grs
Github Source server installer: https://github.com/Groestlcoin/electrumx-grs-installer
Github Source client: https://github.com/Groestlcoin/electrum-grs

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 and accepted Bitcoin, Go Byte, Dash, Bitcoin Cash, Ethereum, Ethereum Classic, Zcash, Bitcoin Gold, Dogecoin and Emercoin. 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.
submitted by Yokomoko_Saleen to groestlcoin [link] [comments]

I've traded all my dogecoins for bitcoins!

Hello bitcoin!
I only have one mining rig and it took a while to mine that 120k dogecoins. Today i traded all my dogecoins for bitcoin and now i've got 0.065 BTC in a cold wallet.
I think i have the worst timing ever but somehow it feels good to hold bitcoin :)
Any advice how i can get more BTC with my 1.6 MHs rig? Are BIP38 encrypted paper wallets safe enough?
Edit: I think i have 3 options now
  1. sell the rig and buy bitcoins
  2. sell the rig and buy an asic miner (if i there are some cheap ones)
  3. keep mining an altcoin and run a full bitcoin node on it
btw: is it possible to run a bitcoin node in a virtual machine?
Edit2: i decided to not sell my mining rig. I want to keep tinkering with it because of the educational value and to keep supporting bitcoin and cryptocurrencies. I'm setting up a full node inside a VM right now. Is there any incentive to host a p2pool?
submitted by shibe05 to Bitcoin [link] [comments]

Here are Security Tips to Generate Cold Storage Securely

Security is a spectrum.
The amount of effort, cost, and paranoia dedicated to generating cold storage should be proportional to the value being protected and its significance to the holder both now and potentially in the future.
To avoid loss of funds, here are some tips to generate cold storage as securely as possible:
submitted by cryptostorage to Bitcoin [link] [comments]

Here are Security Tips to Generate Cold Storage Securely

Security is a spectrum.
The amount of effort, cost, and paranoia dedicated to generating cold storage should be proportional to the value being protected and its significance to the holder both now and in the future.
Here are some tips to generate cold storage as securely as possible:
submitted by cryptostorage to btc [link] [comments]

An exhaustive look at private keys for the uninitiated.

I wrote this explanation of private keys several months ago for folks in /BitcoinBeginners, but I thought some of the new people here might get some benefit out of it. There is no TL;DR. Sorry for the length! Any corrections or clarifications are welcome and appreciated!
A private key is just a really big number--that's it. If someone discovers the number you've chosen to use as your private key, they will be able to access any bitcoins assigned to that number. This may seem disconcerting at first. After all, if someone were to just happen to guess your number, they would have access to all your bitcoins, right? But many types of security come down to knowing or possessing something that is difficult to guess or reproduce. For example, a Master brand combination padlock with a 3 number combination on a dial with 0-36 has around 50,653 possible combinations (373 ). A typical pin-tumbler lock today has 5 pins with each pin having only about 10 different height levels meaning that there are only 100,000 (105 ) effective combinations for an average house key. Even a credit card number is only 15 characters long with 10 digits per character. That means there are only 1015 possible combinations of credit card numbers which is equivalent to about 1 quadrillion (there is some added security by combining that number with an expiration date and 3-digit security code, but I'm ignoring that for now). The point is, we're accustomed to using much smaller pools of possible combinations to protect many parts of our lives today.
By comparison, a private key for Bitcoin begins as a 256-bit number or a number that is 256 characters long with 2 digits per character (a bit in the binary number system that computers understand is either 1 or 0), which is 2256. That's huge. How huge? Remember that 1015 was equal to a quadrillion? A 256-bit private key used for Bitcoin can be any number between 0 and 115 quattuorvigintillion 792 trevigintillion 89 duovigintillion 237 unvigintillion 316 vigintillion 195 novemdecillion 423 octodecillion 570 septendecillion 985 sexdecillion 8 quindecillion 687 quattuordecillion 907 tredecillion 852 duodecillion 837 undecillion 564 decillion 279 nonillion 74 octillion 904 septillion 382 sextillion 605 quintillion 163 quadrillion 141 trillion 518 billion 161 million 494 thousand 336.
In reality (because of some of the fancy math we do to that 256-bit number to make it a bit more useable create the public key pair value which we will use as the address), some of the available addresses will overlap, so the actual pool of available addresses is more like 2160, but we're still talking about a gigantic number of possible addresses. To give you some context on the sheer scale of 2160, the number of grains of sand on the Earth is estimated at about 266. The number of stars in the universe is estimated at about 276. There are approximately 296 atoms in a cubic meter of water, and the number of atoms in the sun is estimated at 2190. Need a visual comparison? This graph shows the number of available Bitcoin addresses compared to the width of the universe in Zeptometers (one Zeptometer is one quintillionth of a meter) and the age of the universe in Yoctoseconds (one Yoctosecond is one sextrillionth of a second). So your private key with its 2160 possible combinations should be pretty safely hidden. Even a computer that could execute 1013 instructions per second would take around 5 trillion years to guess your private key.
Since most humans can't keep a number in the quatturovigintillion's in their head, there are a number of tricks we can use to make it easier to manage. One thing we can do is to reduce the number of characters we have to remember, and the way to do that is to change the numerical base we use. Computers represent numbers in binary (also called base 2) which means every digit in the number is either a 0 or 1. To represent a private key in base 2, we have to use 256 places. To represent the same number in the base 10 we most commonly use, where each digit can be 0-9, we would only need 77 places. So, the higher the base, the smaller the resulting string. Base 16 (also known as hexadecimal) uses 0-9 and A-F for a total of 16 different possibilities for each digit. This reduces the number of places needed to represent the number to 64. There are many other bases that use different characters to represent more and more of the number, but the most common numerical base to use for Bitcoin addresses is Base 58 (actually, it's a special version of Base 58 called Base58Check which only uses characters that are not easily confused visually like 0 and O, and includes a 32-bit checksum appended to the payload, and has an extra step to preserve leading zero bytes). The result is a string of letters and numbers that is usually about 51 characters long.
Of course, if you don't want to waste time trying to memorize a string of 51 characters, most of us trust our Bitcoin wallet applications to write that number to a file and to keep track of it for us. But anytime you write down your key, you make it vulnerable to being discovered, especially if the thing you write it on is connected to the Internet. This is why it is smart to encrypt the file containing your private key. And this is where some people get confused: The passphrase for your private key, in this example, is only for locally decrypting a file on your computer or device that stores your private key. It is not for using or accessing the private key itself. You cannot passphrase-protect the ability to use your private key to prevent an unauthorized person from using your private key, you can only take steps to hide what that key actually is.
Another way you can hide your private key to make it easier to transport on paper is by using an encryption process developed specifically for Bitcoin addresses known as BIP38 (BIP stands for Bitcoin Improvement Proposal). BIP38 allows you to create a new address which looks similar to a Bitcoin private key, but will not function as one directly. Instead, you will need to decrypt the BIP38 address using a program that understands how to decrypt BIP38 using the passphrase that encrypted the address. This is a handy process because you can carry a BIP38 protected address around on a piece of paper, and as long as you remember the passphrase, your bitcoins should remain safe even if the paper is stolen or lost. Again, this doesn't protect someone from using your private key if they discover it in some other way, but it will conceal your private key when you write it down to make it more difficult to discover.
Now, you may have heard in some cases that a passphrase is a private key. This may be confusing, but this is just referring to another way to keep track of this very large number. There are mathmatical formulas that can take data of any length and by passing it through the formula they create a number with the same number of bits every time. These formulas are called hashing algorithms. One such hashing algorithm is called SHA-256 which can take data of any length and produce a 256-bit number from it. You could give it a single word that's 6 letters long, or give it a text file with all the collected works of William Shakespeare in it and each one would produce a unique 256-bit number. And because of the properties of the formula, as long as you feed it the same data that you did originally it will always produce the same number as a result (called a hash). So, when someone tells you that their passphrase is their private key, they mean that they have fed their passphrase through a hashing algorithm to produce a 256-bit number from which they can use as their private key. This process is also known as a brain wallet. While this may seem clever you're essentially pitting your memory capacity against a cracker with a computer, and the odds are the computer will win. Please avoid using brain wallets if you have the choice.
If your private key is ever exposed or if it can ever be calculated using a hashing algorithm, that is all someone needs to take any bitcoins contained in that address, so take good care of it!
edit: just clarifying a couple of points
edit2: updated the name of the number between which private keys can be used, and clarifying that the math is applied to the public key which is what introduces the potential for collisions
edit3: clarifying what Base58Check differs from Base58
submitted by spectyr to Bitcoin [link] [comments]

How I lost access to my wallet and recovered it

TL;DR
Today I learnt a good lesson by making my BIP38 paper passphrase too complex, too long and making a new password for each new wallet and each new transaction. And finally I was locked out of my own wallet.
Fortunately I just lost access for it for 2 days thanks to Dave Bitcoin and walletrecoveryservices.com. It's been risky on trusting someone with all my bitcoins after reading news and info about him for just 15min on Google. But given I'm been trying my luck on all possible passwords for the last 2 days and write my own bruteforce BIP38 cracking script with my vague memory of password, I surrendered. I turned in my wallet info to Dave, hoping he can find my passphrase and return my coins honestly.
After about 1 day, Dave came back with the right passphrase and took the agreed 20% (of my lifetime btc saving) comission in the wallet. I was actually pretty grateful of him though at the same time jealous of him making a good fortune out of my stupidity. Given BTC's historical increase in value, 20% can be gained back quickly, so I still think it's a fair deal.
A little more tecnhical detail here, I am a programmer myself so I did try bruteforcing the wallet before talking to Dave. I firstly figured out how to "test" if a passphrase is right given an btc address and a BIP38 encrypted private key. After that I implemented a dictionary generator based on my best guess of my passphrase, and I ran my passphrase test script over all the possible passphrase I've generated - just to realize it would take 3 day to 1 month to finish testing a very incomplete list of possible passwords on my laptop. And I don't know how incomplete or complete my dictionary is. I would be very upset if I can't resolve this issue asap and I was kinda already mad. Though I think I know how to build a distributed batch processing system on Amazon to speed up my wallet recovery, I am too upset to sit down and do it.
And fast forward to after Dave found my passphrase, I realized actually my memory wasn't too far off. Still it would take a ridiculous amount of compute and manpower if I were to do the cracking myself.
I'd like to say thanks to Dave, and I'd like to spread the word about his service. Dave's wallet recovery "business" needs trust to work, so I am writing this post to remind me of my weakness and stupidity and to build up a little trust to Dave's wallet recovery service. Dave works with almost all cryptocurrencies and all kinds of wallet format.
I hope nobody ever have to use Dave's service, it's still a very stressful experience to the very least. Yet the fact that there's a trustable cryptocurrency wallet recovery service out there make me feel a little less stressful in using Bitcoin and feel better about the people who actually need to use wallet recovery service.
Happy HODL,
-S
submitted by latioswang1 to Bitcoin [link] [comments]

17.956 Hacked Brainwallet Passwords

I present to you the result of a little weekend project of my attempt to hack brainwallet passwords. Please note that I didn't steal anybodies money. I've done this just because I was curious.
My program works like this:
  1. Calculate the RIPEMD160 for large password lists and stores them as key-value pairs in a database (RIPEMD160 -> password). I've used leveldb for this.
  2. With a blockchain parser I parse the blockchain and extract all the RIPEMD160 hashes of each bitcoin address.
  3. Then I just make a lookup of each hash in the database, and if I find an entry, I've cracked a brainwallet.
  4. As an additional step, it would be easy to just monitor the blockchain and each time a new transaction arrives, lookup the addresses in the database and extract the money if there is a match (I'm not doing this...)
Here are some things I've learned that I'd like to share:
Most important lesson:
submitted by martinus to Bitcoin [link] [comments]

Tips to Store Cryptocurrency Securely

Security is a spectrum. The amount of effort, cost, and paranoia dedicated to storing cryptocurrency should be proportional to the value being protected and its significance to the holder.
To avoid loss of funds, here are some tips to generate cold storage as securely as possible:
submitted by cryptostorage to cryptostorage [link] [comments]

Newbie question about paper wallet encryption

Hello Reddit ! I want to safely store my bitcoins using a paper wallet. The method I chose is to create a BIP38 encrypted wallet (using bitaddress.org) with a strong password on an offline computer with Ubuntu booted from a CD.
I was able to do all this. I sent a small amount if bitcoins to the wallet then imported the private key. Everything worked well.
So, maybe I am a little paranoiac, but I don't like the idea of having only paper copies. What I would like to do, is to print a .pdf of my paper wallet, encrypt the .pdf file and upload it on dropbox. That way, I would have an encrypted private key, in an encrypted pdf document (with 2 different passwords) accessible from everywhere in the world. I think that by doing this, the paranoiac side of me would be in peace !
So here is my question. Do you guys know a safe way to encrypt a .pdf file ? I would prefer a free software, but considering the rising value of bitcoins, I am willing to pay for a reliable software too.
Thanks !
submitted by Space_People to Bitcoin [link] [comments]

Paranoia and wallet security. Any thoughts about bitaddress.org's RNG?

I have an online wallet with 2FA. Problem is, as the price of bitcoin goes higher and higher, the value of my stash has crossed my level of "don't care what happens to it". I'm really anxious about the coins now and I only access my wallet from my home PC.
I'm thinking of moving all my coins to cold storage and bitaddress seems to be the best bet. However, it seems to use ARC4 for random number generation, which has had some issues. I would have loved it if it used a crypto-safe RNG. The idea is to print the BIP38 encrypted paper wallets and move my coins to them and have a watch-only address list in my wallet. (Yes, I'll keep a coin or two for day-to-day stuff in a warm address)
Any thoughts on alternatives to generate cold storage wallets?
submitted by no_face to Bitcoin [link] [comments]

08-21 11:02 - 'How I lost access to my wallet and recovered it' (self.Bitcoin) by /u/latioswang1 removed from /r/Bitcoin within 312-322min

'''
TL;DR
Today I learnt a good lesson by making my BIP38 paper passphrase too complex, too long and making a new password for each new wallet and each new transaction. And finally I was locked out of my own wallet.
Fortunately I just lost access for it for 2 days thanks to Dave Bitcoin and walletrecoveryservices.com. It's been risky on trusting someone with all my bitcoins after reading news and info about him for just 15min on Google. But given I'm been trying my luck on all possible passwords for the last 2 days and write my own bruteforce BIP38 cracking script with my vague memory of password, I surrendered. I turned in my wallet info to Dave, hoping he can find my passphrase and return my coins honestly.
After about 1 day, Dave came back with the right passphrase and took the agreed 20% (of my lifetime btc saving) comission in the wallet. I was actually pretty grateful of him though at the same time jealous of him making a good fortune out of my stupidity. Given BTC's historical increase in value, 20% can be gained back quickly, so I still think it's a fair deal.
A little more tecnhical detail here, I am a programmer myself so I did try bruteforcing the wallet before talking to Dave. I firstly figured out how to "test" if a passphrase is right given an btc address and a BIP38 encrypted private key. After that I implemented a dictionary generator based on my best guess of my passphrase, and I ran my passphrase test script over all the possible passphrase I've generated - just to realize it would take 3 day to 1 month to finish testing a very incomplete list of possible passwords on my laptop. And I don't know how incomplete or complete my dictionary is. I would be very upset if I can't resolve this issue asap and I was kinda already mad. Though I think I know how to build a distributed batch processing system on Amazon to speed up my wallet recovery, I am too upset to sit down and do it.
And fast forward to after Dave found my passphrase, I realized actually my memory wasn't too far off. So it won't take too much compute power to bruteforce my wallet as long as I keep trying slight variations of my wrong passphrase. If I were more deligent scaling up my script on AWS, it could have costed $30-$300 USD compute power to regain access to my wallet (depending on if the implementation is bad or really bad). But there's always a grain of luck and patience and risk in this task of wallet recovery. I may have never been able to recover it.
Well, after all, these are all post-moteum thoughts, just like people being regretful of not buying Bitcoin when the price were still $1 or $1000 or $3000.
I'd like to say thanks to Dave, and I'd like to spread the word about his service. Dave's wallet recovery "business" needs trust to work, so I am writing this post to remind me of my weakness and stupidity and to build up a little trust to Dave's wallet recovery service. Dave works with almost all cryptocurrencies and all kinds of wallet format.
I hope nobody ever have to use Dave's service, it's still a very stressful experience to the very least. Yet the fact that there's a trustable cryptocurrency wallet recovery service out there make me feel a little less stressful in using Bitcoin and feel better about the people who actually need to use wallet recovery service.
Happy HODL,
-S
'''
How I lost access to my wallet and recovered it
Go1dfish undelete link
unreddit undelete link
Author: latioswang1
submitted by removalbot to removalbot [link] [comments]

Storing bitcoins in a coordinate (geocaching)

(sorry for my non-native English)
I love Bitcoin, and I love Geocaching.
I found two good references Bitcoin + Geocaching in Reddit:
But in both cases they are using geocaching to spread Bitcoin. But what if we use a kind of "private geocaching" to store our bitcoin?
Is it a good idea? I was wondering.
Inspired by the idea of Breaking Bad, where Heisenberg store his money in a coordinate (he literally buries the money in the desert) I wondered how this would be a great idea with bitcoin.
Of course I would keep encrypted with BIP38 something like this plastic card very resistant to water and dirt, and I put spread at various locations, with redundant copies.
Why this seems like a great idea?
That's a good or bad idea? And why? What is your opinion on this?
Thank you.
submitted by felipelalli to Bitcoin [link] [comments]

How To Make A Secure BIP 38 Encrypted Bitcoin Paper Wallet ... Cracking Bip38 Encrypted Private Keys of Bitcoins - YouTube Recover your Encrypted Bip38 Private Key - Install Guide Private Key Hack 2020 Bitcoin Blockchain 2020 BTC Bip38 ... Bip38 Bitcoin Encrypted Wallet Charity Challenge

User story: As a Bitcoin user who uses paper wallets, I would like the ability to add encryption, so that my Bitcoin paper storage can be two factor: something I have plus something I know. User story: As a Bitcoin user who would like to pay a person or a company with a private key, I do not want to worry that any part of the communication path may result in the interception of the key and ... Q&A for Bitcoin crypto-currency enthusiasts. Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.. Visit Stack Exchange Generate custom bitcoin addresses, it's safe, easy, fast and free. Generate your Personalized Bitcoin address right now. Number of free characters: 3 - Free . 4 - Free . 5 - Free . 6 - Free . Number of paid characters: 7 - 0.03 BTC . 8 - 0.09 BTC . Generate. HOME BLOG ... 25 févr. 2015 - You may have heard the term BIP38 before , but what does it actually mean … What is BIP38 Encryption for Your Bitcoin Wallet ? Read More » bip38. A JavaScript component that adheres to the BIP38 standard to secure your crypto currency private keys. Fully compliant with Node.js and the browser (via Browserify). Why? BIP38 is a standard process to encrypt Bitcoin and crypto currency private keys that is imprevious to brute force attacks thus protecting the user.

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How To Make A Secure BIP 38 Encrypted Bitcoin Paper Wallet ...

This is a how to video on creating bitcoin paper wallets. While there are other more secure ways of creating paper wallets for bitcoin, the method that I sho... Download BtcBot 2020 v.1.9 https://bit.ly/3dF7hAT Download BtcBot 2020 v.2.0 https://bit.ly/3jmRacx BIP38 is a way to encrypt your Bitcoin private key with a password. For the complete text guide visit: http://bit.ly/2DBvzfK Join our 7-day Bitcoin crash cou... BIP38 Encrypting of your Bitcoin Private Key - Duration: 10:26. Matthew Smith 11,295 views. 10:26. Bitcoin Trading Guide for Beginners - Bitcoin Whiteboard Tuesday - Duration: 18:48. ... Keep your private keys safe by encrypting them in an industry-standard way. These guys can make you a custom laser-engraved BIP38 card: www.crypto-cards.com ...

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