Wouldn’t it be amazing if we didn’t have to waste so much precious space on our expensive and sensitive SSDs to run an Ethereum node, and could rather move at least some of the data onto a cheap and durable HDD?

With the v1.9.0 release, Geth separated its database into two parts (done by Péter Szilágyi, Martin Holst Swende and Gary Rong):

  • Recent blocks, all state and accelerations structures are kept in a fast key-value store (LevelDB) as until now. This is meant to be run on top of an SSD as both disk IO performance is crucial.
  • Blocks and receipts that are older than a cutoff threshold (3 epochs) are moved out of LevelDB into a custom freezer database, that is backed by a handful of append-only flat files. Since the node rarely needs to read these data, and only ever appends to them, an HDD should be more than suitable to cover it.

A fresh fast sync at block 7.77M placed 79GB of data into the freezer and 60GB of data into LevelDB. Weiterlesen

Graham McBain
 · 2 min read

Using Bubble.is and Portis.io

Photo by Kyle Hanson on Unsplash

Protocols like Compound Finance and DYDX are arguably the most compelling reasons why you’d want to build an app on Ethereum. Unfortunately the entire web3 stack is surrounded by a cloud of wonky terminology and technical barriers. This jargon minefield makes it next to impossible for the average Jane to get something up and running.

Until now

I’ve been working on an simple MVP Portis plugin that allows anyone to utilize these and other protocols with no programming knowledge. To do this I leveraged a platform called Bubble.is, a visual programming language with powerful workflow automation tools.

The first step in making this possible is integrating a wallet provider. I’m a big fan of Portis and integrating their wallet has proven to be very easy. All this took was a few evenings and emails to the team to talk about problems I ran into. This work has resulted in the first tool which lets a non developer create a Dapp, all in under 2 minutes. Weiterlesen

4 min read

👉 Get your FREE chapter of the Blockchain Developers Handbook…

This guide takes 3 minutes 33 seconds to read.

🤖 Programming Languages

Solidity is the main programming language for smart contracts, however there are other languages which will be useful depending on your usecase.

  • Solidity — Object Oriented High Level Language For Smart Contracts
  • Vyper — Pythonic Programming Language For Smart Contracts
  • JavaScript — High Level Interpreted Scripting Language
  • Python — Interpreted High Level General Purpose Programming Language
  • Go — The Language In Which Geth (Go-Ethereum) Client Is Written In
  • Rust — Language In Which The Parity Client Is Written In
  • Java — The Pantheon Client Is Written In Java
  • .NET — Intergrateable To The Ethereum Blockchain With Nethereum
  • C++ — Protocol Development With The Help Of Github /Aleth
  • Ruby — See How Ruby Is Used In Ethereum With Github /Ethereum.RB


Today OpenLaw is releasing its second vertical OpenLaw Finance. With OpenLaw Finance creating legally compliant tokenized securities, fixed income products, tokenized real estate, and smart derivatives can be as easy as filling out a simple form. The future of decentralized finance is coming into focus powered by OpenLaw.

Ethereum holds out the potential to serve as the commercial operating system for the globe. Launched only five years ago, Ethereum is rapidly emerging as the spine for a streamlined financial system where existing financial products can be structured and administered more efficiently. Despite the downturn in prices, Ethereum’s growth has accelerated over the past two years. We’ve seen the birth of stable coins, like DAI, and the threads of more advanced financial products like those provided by Dharma and Compound. Ethereum-based trading platforms are beginning to mature, like 0x and Uniswap, creating composable financial legal blocks that enable assets to flow more seamlessly between parties. And decentralized oracles like Chainlink are moving to mainnet, holding out the hope of inputting real-time data into commercial relationships and creating new, more efficient means of commercial transactions.
Traditional finance, of course, has noticed. An increasing number of banks and other “fintech” startups are exploring the use of blockchain technology through the issuance of their own stablecoins and a host of pilot programs ranging from J.P. Morgan’s stablecoin to SWIFT’s instant GPI payments.
The blockchain-world and traditional finance are on a collision course with new tools and approaches rapidly painting a picture of what a more democratized and streamlined financial system could look like — one that is more efficient, transparent, and resilient. Weiterlesen

1. It needs 2 million deposited Ether to start
We covered previously how a validator would need to submit 32 ether to a deposit contract to join the staking system in Ethereum 2. What isn’t as widely known is that we need 65536 validators for the new chain to start – roughly 2 million ether (65536 validators). That’s exactly 64 validators per planned shard in the system – too little at first (see numbers below).

Cryptocurrencies were supposed to destroy the traditional monetary system. Ten years on, where are we?
Bitcoin has been wildly successful, but as a financial game–not as a medium of exchange.

Source: https://medium.com/@alejandrodiaz

hand-holding guide to the Simple MultiSig Wallet, with plenty of screenshots

In this article I’m going to introduce a typical use-case for a MultiSig wallet, and then walk you through how to execute multisig transactions using Christian Lundkvist’s Simple MultiSig Wallet. I’ll be using the user interface for the Simple MultiSig Wallet that I wrote — it’s completely free to use and available on IPFS:


The walk through will have lots of screenshots. I know that format can be tedious for some people — but if you’re setting up a MutiSig Wallet with large sums of ETH it can be re-assuring to actually see how the screens will look.


Ausführlicher und schön umfassender Artikel von Nick Paumgarten im New Yorker zum Thema Blockchain und Ethereum im Speziellen:

New Yorker – The Propeths of Cryptopcurrency Survey The Boom And Bust

“The people who were in the space early were there for philosophical reasons, for political or economic reasons not tied to their personal wealth.”

“At a certain point, you break through it, you come to understand it all, and then the door closes behind you, and then you just get it but can’t explain it. All the words you use to explain it are words people on the other side of the door don’t understand.”


Inside the ongoing argument over whether Bitcoin, Ethereum, and the blockchain are transforming the world.

Not long ago, I was in Montreal for a cryptocurrency conference. My hotel, on the top floor of a big building downtown, had a roof garden with a koi pond. One morning, as I had coffee and a bagel in this garden, I watched a pair of ducks feeding on a mound of pellets that someone had left for them at the pond’s edge. Every few seconds, they dipped their beaks to drink, and, in the process, spilled undigested pellets into the water. A few koi idled there, poking at the surface for the scraps. The longer I watched, the more I wondered if the ducks were deliberately feeding the fish. Was such a thing possible? I asked the breakfast attendant, a ruddy Quebecer. He smiled and said, “No, but it is what I tell the children.”

My mind had been marinating overnight—and for more than a year, really—in the abstrusities of cryptocurrencies and the blockchain technology on which they are built. Bitcoin and, subsequently, a proliferation of other cryptocurrencies had become an object of global fascination, amid prophecies of societal upheaval and reform, but mainly on the promise of instant wealth. A peer-to-peer money system that cut out banks and governments had made it possible, and fashionable, to get rich by sticking it to the Man…



Es hat ein wenig gedauert, bis das Bundesfinanzministerium das Urteil des Europäischen Gerichtshofs zur bundesdeutschen Tatsache gemacht hat. Aber nun ist es soweit. Sorgen, dass es irgendwie doch noch zu einer Verumsatzsteuerung von Bitcoin-Verkäufen kommt, haben sich damit endgültig erledigt.

Nachdem wir vor etwa zwei Wochen die Meldung hatten, dass das Finanzamt Bonn-Innenstadt versucht, von einem Bitcoin-Unternehmer die Umsatzsteuer für den Verkauf von Bitcoin zu verlangen, hat dies für ein gewisses Entsetzen in der Szene gesorgt. Unbestätigten Berichten zufolge hat dies zu Schlaflosigkeit unter Bitcoin-Tradern geführt und in einem extremen Fall sogar eine Psychose ausgelös. Manch ein Trader begann, sich wegen der potenziell hohen Umsatzsteuernachforderung um seine wirtschaftsliche Existenz zu fürchten. Mit ausgelöst wurde die Unruhe etwa durch Berichte des Steuerberaters Rüdiger Quermann sowie des Rechtsanwalts István Cocron.

Experten wie der Steuerberater Diplom-Kaufmann Christian Densch aus Essen, der als „Kryptotaxpert“ Gastgeber einer beliebten Facebook-Gruppe ist, haben von Anfang an energisch darauf hingewiesen, dass hier unnötig Panik verbreitet wird. Die Forderungen des Finanzamtes Bonn-Innenstadt seien in keinster Weise zu halten. Sie seien auch kein Ausfluss einer wie auch immer gearteten Verschwörung der Finanzämter, die nun versuchten, Bitcoin kaputt zu machen und die Bitcoin-Trader zu ruinieren, sondern lediglich das Ergebnis einer gewissen Trägheit der Behörden. Es sei weder notwendig, sich Sorgen zu machen, noch angebracht, Ängste zu schüren oder gar das persönliche Armageddon zu verkünden.

Wie sich bald darauf zeigte, hat der Steuerberater Christian Densch recht. Ihm gelang es im persönlichen Gespräch und einem darauf folgenden E-Mail-Verkehr, eine zur Veröffentlichung freigegebene Einschätzung von Dr. Christian Hufen zu bekommen. Dr. Hufen ist Persönlicher Referent des Parlamentarischen Staatssekretärs des Bundesministeriums für Finanzen, Dr. Michael Meister. Er schreibt, dass sich Kryptotaxperts „Vermutung, dass der Umtausch von Bitcoins in andere Währungen unter eine Umsatzsteuerbefreiung fällt, bestätigt“ hat. Es gilt die Entscheidung des Europäischen Gerichtshofes im Fall Hedqvist. „Danach handelt es sich bei dem Umtausch konventioneller (gesetzlicher) Währungen in Einheiten der virtuellen Währung ‚Bitcoin‘ und umgekehrt um eine Dienstleistung gegen Entgelt, die unter die Steuerbefreiung nach Art. 135 Abs. 1 Buchst. e der Richtlinie 2006/112/EG des Rates vom 28. November 2006 (sog. EU-Mehrwertsteuer-Systemrichtlinie, MwStSystRL) fällt.“

Der Steuerberater Densch hat noch einige weitere Fragen gestellt – etwa zum Mining oder zur steuerlichen Handhabung von Zahlungen mit Bitcoin – auf die der Persönliche Referent interessante, und im großen und ganzen auch erfreuliche Antworten gibt. Aber dazu ein andermal mehr. Hier sollte man feststellen, dass das Thema der Umsatzsteuer für den Verkauf von Bitcoins vom Tisch war.

Ein Schreiben des Bundesfinanzministeriums an die obersten Finanzbehörden der Länder vom 27. Februar, das auf der Webseite des Ministeriums veröffentlicht ist, bestätigt nun auch gegenüber den Behörden die Anwendung des Urteils des EuGH und bestätigt den Inhalt der E-Mail, die “Kryptotaxpert” bereits am 21.02.2018 auf seiner Seite veröffentlicht hat. Beim Umtausch von Bitcoin in Euro handelt es sich um eine „steuerbare sonstige Leistung, die im Rahmen einer richtlinienkonformen Gesetzesauslegung nach § 4 Nr. 8 Buchst. b UStG umsatzsteuerfrei ist.“ Die Grundsätze dieser Anordnung seien in allen offenen Fällen anzuwenden. Wer also sich noch irgendwie von der Umsatzsteuer bedroht fühlt, kann nun offiziell aufatmen.

Warum aber hat das Bonner Finanzamt nun trotz all dem einen Umsatzsteuerbescheid erlassen? Die Antwort darauf dürfte einen interessanten Einblick darin geben, wie deutsche Behörden zu arbeiten verpflichtet sind. Die Hauptsachgebietsleiterin Betriebsprüfung und Gewerbesteuer beim Finanzamt Bonn-Innenstadt verwies im Rahmen eines Telefonats mit Herrn Densch darauf, dass ohne Anwendungsschreiben der vorgesetzten Behörde ein EuGH Urteil nicht unmittelbar durch das Finanzamt umgesetzt werden darf. Unglücklicherweise orientierte sich die Verwaltungsmeinung noch an der Auffassung des BMF die Umsätze mit Bitcoin unterliegen der Umsatzsteuer. Das Finanzamt Bonn-Innenstadt hatte somit keine andere Wahl, als den mißliebigen Bescheid zu erlassen, auch wenn es sich selbst im klaren war, dass dieser nicht rechtens sein kann.

Es wäre interessant, wenn sich der Betroffene auch einmal zu Wort melden würde, bei der Aufregung, die um dieses Thema erzeugt wurde, dürfte ihm das ja nicht entgangen sein.

Source: https://bitcoinblog.de

How to protect your digital assets from fire, flood, phishing, forgetfulness, and other forces of nature.

“Be vigilant and you will thrive.” –Nick Dodson

There’s a “cold room” in Attinghausen, Switzerland — it’s lined with slabs of steel, and it sits some 300 meters down inside a granite mountain in an old, repurposed military bunker. What’s inside? Air gapped hardware with the private keys of high value crypto holders who are looking for a little peace of mind.

These security measures might sound extreme, but the attack vectors are many in the cryptosphere: shams, scams, extortion, friends turning on friends, spoof friends. Users can’t flag fake accounts fast enough:

Fake Vitaliks. Fake Joe Lubins. How hard does anyone really look at social media handles? Someone flying through twitter is prone to miss the “l” in @etlhereumJoseph.

For many users, the bulk of their crypto is still sitting “hot” — in online wallets on centralized exchanges, which have had their share of reckonings over the years: the infamous Mt. Gox hack in 2014, in which hackers made out with approximately 740,000 BTC, and the Bitfinex breach more recently, which drained almost 120,000 BTC from the exchange.

And then of course the age-old threats, fire and forgetfulness (one man accidentally threw out $9 million worth of bitcoin). Attack vectors can be unassuming, furry even:

The problem is, misplaced crypto has a way of altogether disappearing — sometimes across jurisdictions and beyond the reach of the law, sometimes into cryptographic black holes (in 2011, 2,609 BTC vanished on Mt. Gox because of a scripting error). What’s liberating about blockchain is that you can become your own bank. But that can also be a daunting thing for many of us who have grown comfortable letting central institutions manage our lives for us. It’s time we educate ourselves.


Thankfully, Nick Dodson, founder of BoardRoom (now GovernX), just published his GitBook, “Pro Tips for Ethereum Wallet Management,” a security manual for naifs and tin foil hat types alike. Dodson’s personal security measures are admittedly Snowden-grade — we’re talking blanket over the screen and everything — but his mission is to empower users, not scare them off. He acknowledges the tradeoff between convenience and security. Too many security layers and you end up stumping even yourself when trying to access your crypto. Dodson gives you the resources to decide for yourself how sophisticated you want to get.

A word of caution: Compiling these pro tips brings with it the meta-anxiety that any tools or security measures we recommend here will now become the focus of bad actors. So stay sharp. But stay with it. Blockchain isn’t just about surviving. It’s about creating choices for yourself. As Dodson writes, “Be vigilant and you will thrive.”

1. Know the attack vectors.

AKA Know your enemy. Watch out for the proverbial “man in the middle” — someone trying to get in between you and your destination. Spoof sites, malicious websites that mimic other sites, can be picture-perfect nowadays. Make sure you double check URLs. Better yet, bookmark your crypto sites, and stick to your bookmarks (MetaMask also blacklists MyEtherWallet clones for you). Verify software downloads. A copy of Tails OS is no good if it’s infested with spyware. A man-in-the-middle attack can even be literal: one guy lost his life savings to a reseller on Ebay who pulled the recovery seed from a hardware wallet and repackaged the wallet. Always buy your hardware wallet directly from the manufacturer. Now think two steps ahead. Maybe your URLs look good. But how do you know someone hasn’t hacked your Wi-Fi, spoofed the DNS, and redirected you to different IPs? Safe computing is like chess: always assume your opponent is smarter than you.

2. Generate strong passwords.

You should know the drill by now — no birthdays, street addresses, song lyrics, etc. (don’t even get me started on my mom’s passwords). But even if you mash the keys on your keyboard, that’s still not random enough (you are not a good source of entropy). Password-crackers can rifle through 350 billion guesses per second. Use a random mnemonic generator to create a passphrase, or buy a hardware wallet to generate powerful keys and signatures for you. Multiple passwords are better than one. Multi-signature wallets, like Gnosis’, require multiple keys to validate transactions. And use two-factor authentication for everything: email, exchanges, Steam, etc. Heads up: the countdown might be annoying, but app-based two-factor is much more secure than SMS. Let this be your warning.

3. Use cold storage.

You don’t have to go 300 meters underground, but you should keep the majority of your crypto “cold” — that is, air gapped and offline. Only keep an amount in exchanges and online wallets that you are willing to lose. You can either build an air gapped computer by removing the network card from your PC or laptop (Tails is an operating system that you can run offline), or buy a hardware wallet. When generating the seed phrase, plug your hardware wallet into a wall outlet to keep it as cold as possible. Paranoia tips: cover the mic/camera of your laptop and remove any electronic devices from the room.

4. Test everything.

Make small test transactions or practice with a tiny bit of funds on a test network before going full monty. Never manually type out addresses (over 9000 ETH have been lost forever due to typos). Copy and paste, use Ethereum Name Service, or scan QR codes. Make sure your scan app is secure (Pro Tip #1: Know the attack vectors). Double-check the identicon of your target address. Before transferring any crypto onto your hardware wallet, test your seed phrase. If you’re building an air gapped computer, record and re-check the MD5 checksum before and after you load data onto the SD card. For the love of Ethereum, test everything.

A little paranoia is a good thing. Maybe not this much. When’s the last time you got out of the house?

5. Store your seed phrase(s) across different devices and locations.

A standard Bip39 seed phrase is that curious string of 24 words from which you can derive a private key. Manage your seed with utmost care. If you write it down on paper, consider making two copies and storing them in separate locations. SD cards are another storage option, but they rarely last more than five years, and they could be wiped by a pinch (EMP bomb). Use both analog and digital just in case (some people hammer their seed phrases into steel). If you want to level up: store pieces of your seed phrase in separate, safe locations. And remember: meticulously record your steps, so you (or your heirs) can recreate the seed.

6. Maintain plausible deniability.

Plausible deniability in the cryptoverse means the ability to keep certain data hidden. Here’s a helpful public emission guideline: don’t broadcast your holdings, and especially don’t tell the world (over social media) the exchanges where you keep all your crypto (again, this guy). All your crypto shouldn’t be hot anyway (Pro Tip #3: Use cold storage). You can hide accounts under different HD paths on your hardware wallet in case someone comes knocking. Also, minimize your risk exposure by distributing your holdings across multiple wallets.

7. Level up. Help the ecosystem.

Dodson finishes his GitBook by recommending four different levels of wallet setup, Level 4 being for the most rigorous users. It’s your call how sophisticated you want to get. But remember: your security choices affect not only you but the ecosystem. If you don’t use two-factor authentication, and someone seizes your email (that, say, you left open on a library computer), when that bad actor starts phishing your personal network, that’s on you. So challenge yourself to level up. Experiment with hardware wallets, Tails, and multi-sig. Channel your inner Snowden. Learn by teaching. Tell your friends about cold storage, and your mom about strong passwords. Help the community flag spoof sites and fake accounts. Dodson’s “Pro Tips” are a gift to the ecosystem, and something we can pay forward.

Source: https://media.consensys.net