Angel \”Java\” Lopez on Blog

December 29, 2016

Blockchain: Links And Resources (23)

Filed under: Bitcoin, Blockchain, Ethereum, FinTech, Links, RSK, Smart Contracts — ajlopez @ 11:46 am

Previous Post
Next Post

What 2016 Taught Us About Smart Contracts

Blockchain in Finance: From Buzzword to Watchword in 2016

Global Banks Pilot Blockchain-based Gold Settlement Platform

Bitcoin Prices Break Past $800

BNP Paribas Clients Conduct ‘Live’ Blockchain Payments


Towards a Clearer Understanding of Blockchain’s True Value

Why Blockchain Won’t Be Connecting Banks in 2017

2017: The Year Regulators Engage with Blockchain

ABN Amro Tests Blockchain for Real Estate Transactions

My Links

Stay tuned!

Angel “Java” Lopez

December 25, 2016

Blockchain: Links And Resources (19)

Filed under: Bitcoin, Blockchain, Ethereum, FinTech, Links, RSK — ajlopez @ 9:39 pm

Previous Post
Next Post

RSK: Making the Bitcoin Blockchain More Like Ethereum 2.0 – Blockchain News

Uncle Rate and Transaction Fee Analysis – Ethereum Blog

Blockchain Voting Project Wins $10k Kapersky Labs Prize – CoinDesk

Inside ‘Spark’: Circle’s New Bitcoin-Powered Smart Contract Platform – CoinDesk

‘Sovereign’ Blockchains Will Change Monetary Policy, Bank Paper Argues

Ethereum Research Update – Ethereum Blog

Toward Metropolis: After Blockchain Repairs, Ethereum Looks Ahead – CoinDesk

Smart Contract Issues Set Off ‘Alarm Bells’, Says US Regulator – CoinDesk

Chain Protocol Whitepaper

Solving the Blockchain Industry’s Number One Problem – Talent Shortage

My Links

Stay tuned!

Angel “Java” Lopez

December 6, 2016

Blockchain: Links And Resources (16)

Filed under: Bitcoin, Blockchain, Ethereum, FinTech, Links, RSK — ajlopez @ 10:45 am

Previous Post
Next Post

WINGS: plataforma descentralizada de mercados predictivos reinventa las DAO

Can Blockchain Gain Traction in Power and Energy Markets? – Microgrid Media

US Commerce Department to Discuss Blockchain Copyright – CoinDesk

Intel is Winning Over Blockchain Critics By Reimagining Bitcoin’s DNA – CoinDesk

The Blockchain Milestone You May Have Missed – CoinDesk

Japan’s Central Bank is ‘Test-Driving’ Distributed Ledgers – CoinDesk

Evolution of Kadena, the First Real Private Blockchain – CoinDesk

Coders Named After Harry Potter Characters Join Bitcoin’s ‘Mimblewimble’

R3’s Corda Code Debut Draws Mixed Response – CoinDesk

Bitcoins: la moneda virtual crece en la Argentina y apunta a los clientes no bancarizados

Wings and ForkLog Announce a Contest for Best DAO Concept | ForkLog

My Links

Stay tuned!

Angel “Java” Lopez

December 2, 2016

Blockchain: Links And Resources (15)

Filed under: Bitcoin, Blockchain, Ethereum, FinTech, Links, RSK — ajlopez @ 2:05 pm

Previous Post
Next Post

WeChat-Inspired Wallets Are Coming to Ethereum – CoinDesk

Zcash Prices Are Finally Beginning to Show Some Stability – CoinDesk

What Investors Should Know Before Trading Zcash – CoinDesk

Blockchain Pros Debate ‘Looming Challenges’ for Smart Contracts – CoinDesk

Bitfury Paper Makes Case For Auditability As Blockchain’s Defining Feature

How Developers Are Responding to Ethereum’s Unexpected Fork – CoinDesk

The Most Worrying Slide in the State of Blockchain – CoinDesk

China’s Huiyin Group Launches $20 Million Bitcoin Fund – CoinDesk

Ethereum’s Fourth Blockchain Fork: So Far, So Good

Ether Prices Near 7-Month Low As Blockchain Issues Spook Investors – CoinDesk

Blockchain to become ‘beating heart’ of global financial system

Argentina’s Central Bank is Warming Up to Blockchain – CoinDesk


My Links

Stay tuned!

Angel “Java” Lopez

November 28, 2016

MultiCurrency in Ethererum/RSK (1)

Filed under: Bitcoin, Blockchain, Ethereum, FinTech, Open Source Projects, RSK — ajlopez @ 9:26 am

In my post serie about connecting blockchains, I’m writing about exchange (value one to one, without change of value) between two popular heterogeneous blockchains (BitCoint and Ethereum/RKS). I’m a member of the development team of @RSKSmart, but those posts are personal opinions: the real work by the team was not published yet.

Another path to explore, is to have, in the SAME blockchain, many cryptocurrencies. My thought is that it could be done in Ethereum/RSK.

In Ethereum, there are accounts with state, and the account state includes the cryptocurrency balance for the account. There is a “default” currency, the Ether. But I think this model could be easily extended.

Each account has a currency, too. The “default” cryptocurrency should be the Ether, but some accounts could be created with ANOTHER cryptocurrency as default currencty. Then, they form a separated set of accounts. One account with currency X, can transfer and can borrow value from another account with THE SAME CURRENCY X. In this way, the new set of account could leverage all the infrastructure of Ethereum, to have a pool of accounts that manage a “coloured” currency value, separated from the default/main one.

In the next post, I want to write about:

– How to define a new currency
– How to create an account with a new currency
– How to transfer between accounts with the same currency
– How to transfer between accounts with different currencies

Stay tuned!

Angel “Java” Lopez

November 26, 2016

Connecting Blockchains (6)

Filed under: Bitcoin, Blockchain, Ethereum, FinTech, Open Source Projects, RSK — ajlopez @ 7:07 pm

Previous Post

BitCoin is the best known blockchain. Ethereum is the “new kid on the block”, and it has its similarities and its difference with BitCoin. At first, Ethereum has running nodes, transactions, blocks, and a blockchain build by consensus:

The consensus is based on proof of work for each block added to the blockchain, like in BitCoin. But the internal structure of transactions, the state of world by block, are quite different. For example, there are accounts WITH STATUS, instead of unspent outputs as in BitCoin.

But the main, key difference, is that each account could be an smart contract. Each node has a Ethereum Virtual Machine that can run compiled smart contracts. A method in a smart contract could be invoked in each transaction. This new capability opens lot of new use cases.

Having smart contracts in Ethererum/RSK, is one of the motivation to connect both blockchain: BitCoin is limited, running scripts, and the smart contract world is new brave world to be explored.

Stay tuned!

Angel “Java” Lopez

November 24, 2016

Blockchain: Links And Resources (14)

Filed under: Bitcoin, Blockchain, Ethereum, FinTech, Links, RSK — ajlopez @ 12:15 pm

Previous Post
Next Post

Bitcoin Pioneer Charlie Shrem Launches New Blockchain Venture

Rootstock Announces Turmeric Testnet Release; Interview with Chief Scientist, Sergio Lerner

RSK Labs Launch Release that Combines Ethereum and Bitcoin in One Network

Open Sesame. RSK testnet powered door unlocked via Jaxx! – YouTube

Fermat, the Internet of People and the Person to Person Economy

Blockchain technologies could transform government services | TechCrunch

Blockchain and Ethereum Security on the Higher Level – Vitalik Buterin – YouTube

Blockstream – Covenants in Elements Alpha

Proof of Stake FAQ · ethereum/wiki Wiki

Chandler Guo on The Bitcoin & Blockchain Revolution – YouTube

My Links

Stay tuned!

Angel “Java” Lopez

November 22, 2016

Blockchain: Links And Resources (13)

Filed under: Bitcoin, Blockchain, Ethereum, FinTech, RSK — ajlopez @ 11:06 am

Previous Post
Next Post

Santander Quits R3 Blockchain Consortium – CoinDesk

Blockchain wallet Jaxx integrates Rootstock RSK – ‘Smart Bitcoin’

MedRec: Medical Data Management on the Blockchain · PubPub

ASX Exec Calls for Blockchain Use in Healthcare – CoinDesk

Blockchain Credit Card Trial Puts New Twist on Retail Payments – CoinDesk

Embrace The Coming Bitcoin Fork (1 of 3) – Medium

Whoa… Geth 1.5 – Ethereum Blog

Diego Gutiérrez: El nacimiento de la Internet del valor – Insights Media

Central Bank of Argentina Calls on the Bitcoin and Blockchain Community

Gavin Wood – Polkadot – Vision For A Heterogeneous Multi-chain Framework.pdf

Gavin Wood Cuts Tech Deal with Melonport on Cryptofinancing Hedge Fund Blockchain

CoinDesk R3 Banks Trial Blockchain Identity Registry – CoinDesk

Bitmain Reveals Plans for Major Bitcoin Mining Data-Center in Northwestern China

swarm merge to develop · Issue #2961 · ethereum/go-ethereum

My Links

Stay tuned!

Angel “Java” Lopez

November 14, 2016

A Database in the Blockchain (1)

Filed under: Blockchain, Ethereum, FinTech, Open Source Projects, RSK — ajlopez @ 9:53 am

Having a blockchain with smart contracts, like in Ethereum/RSK, opens a can of possibilities, new use cases, and new ways to give value to business. I’m not sure it is needed, but one possibility to explore is to have a simple relational database associated with an account, using the account storage.

An account can have code (maybe precompiled), balance, nonce, and storage. Storage is composed by storage cell, each having an address (32 bytes), and a content (a big integer represented in 32 bytes). The account storage has a hash value associated: if its content change, the hash changes.

At @RSKSmart, we are experimenting having storage cells with arbitrary binary data (byte arrays of any length). The hash calculation is the same, and the cell persistence does not change: internally, it uses a key-value store, where key is a byte array, and value is a byte array.

Then, I could implement a precompiled contract, with:

– Method execute(sql) to execute a simple SQL statement (create table, insert, ….)
– Method query(sql) to retrieve an array of rows

Internally, each table could have an ID (short number), and each row has an ID (20 bytes address, maybe). The description of the database (one database per account) resides in system tables. The storage cell for a row should be located at TableID + RowID, in the account storage.

In this way, each state of world hash has an snapshot of the account databases, as now they have the account states.

But I insist: maybe there are few use cases where such arrangement add values. Usually, the value comes from contract logic, and more directly exposed state, in contract variables.

I hope to write some demo code.

Another approach is to use the contract as a lightweight wrapper around an industrial-strength distributed database. But it is not clear how to keep the snapshots by world state (and if those snapshots are needed or not).

Stay tuned!

Angel “Java” Lopez

November 12, 2016

Connecting Blockchains (4)

Filed under: Bitcoin, Blockchain, Ethereum, FinTech, Open Source Projects, RSK — ajlopez @ 7:16 pm

Previous Post
Next Post

Let’s add a new use case. To really expand the connection of two blockchains, we can add a “reverse” use case: transfering value from the second blockchain to the first one:

The external mechanism is the same: a transaction to the special account in the second blockchain, should be reflected in a similar transaction in the first blockchain. In this way, the owner of the value, after using it in the second blockchain, can decide to return it to the first circuit.

Given that this second use case resembles the first one, we could expect a similar implementation. It could be the case if both blockchain had the same capabilities. But usually, they are too different.

In the next post, we will start to discuss a CONCRETE pair of blockchain: Bitcoin vs Ethereum/RSK

Stay tuned!

Angel “Java” Lopez

Older Posts »

Create a free website or blog at