The Central Bank Business Model Is Under Attack - CoinDesk

Anyone here think that the DDoS attacks on the various bitcoin exchanges are being funded/done by either governments or central banks around the world?

Just saw this message at bitfloor.com:
"If you are coordinating a DDoS attack, please remember that bitcoin companies are not giant multinationals with huge support staff and computers. We are all involved because we want to see bitcoin succeed. -Roman"
Maybe that's the problem. The people behind the DDoS attacks DONT want btc or ANY crypto-currency to succeed. Anyone else have thoughts on this?
submitted by qwertytard to Bitcoin [link] [comments]

Why i’m bullish on Zilliqa (long read)

Edit: TL;DR added in the comments
 
Hey all, I've been researching coins since 2017 and have gone through 100s of them in the last 3 years. I got introduced to blockchain via Bitcoin of course, analyzed Ethereum thereafter and from that moment I have a keen interest in smart contact platforms. I’m passionate about Ethereum but I find Zilliqa to have a better risk-reward ratio. Especially because Zilliqa has found an elegant balance between being secure, decentralized and scalable in my opinion.
 
Below I post my analysis of why from all the coins I went through I’m most bullish on Zilliqa (yes I went through Tezos, EOS, NEO, VeChain, Harmony, Algorand, Cardano etc.). Note that this is not investment advice and although it's a thorough analysis there is obviously some bias involved. Looking forward to what you all think!
 
Fun fact: the name Zilliqa is a play on ‘silica’ silicon dioxide which means “Silicon for the high-throughput consensus computer.”
 
This post is divided into (i) Technology, (ii) Business & Partnerships, and (iii) Marketing & Community. I’ve tried to make the technology part readable for a broad audience. If you’ve ever tried understanding the inner workings of Bitcoin and Ethereum you should be able to grasp most parts. Otherwise, just skim through and once you are zoning out head to the next part.
 
Technology and some more:
 
Introduction
 
The technology is one of the main reasons why I’m so bullish on Zilliqa. First thing you see on their website is: “Zilliqa is a high-performance, high-security blockchain platform for enterprises and next-generation applications.” These are some bold statements.
 
Before we deep dive into the technology let’s take a step back in time first as they have quite the history. The initial research paper from which Zilliqa originated dates back to August 2016: Elastico: A Secure Sharding Protocol For Open Blockchains where Loi Luu (Kyber Network) is one of the co-authors. Other ideas that led to the development of what Zilliqa has become today are: Bitcoin-NG, collective signing CoSi, ByzCoin and Omniledger.
 
The technical white paper was made public in August 2017 and since then they have achieved everything stated in the white paper and also created their own open source intermediate level smart contract language called Scilla (functional programming language similar to OCaml) too.
 
Mainnet is live since the end of January 2019 with daily transaction rates growing continuously. About a week ago mainnet reached 5 million transactions, 500.000+ addresses in total along with 2400 nodes keeping the network decentralized and secure. Circulating supply is nearing 11 billion and currently only mining rewards are left. The maximum supply is 21 billion with annual inflation being 7.13% currently and will only decrease with time.
 
Zilliqa realized early on that the usage of public cryptocurrencies and smart contracts were increasing but decentralized, secure, and scalable alternatives were lacking in the crypto space. They proposed to apply sharding onto a public smart contract blockchain where the transaction rate increases almost linear with the increase in the amount of nodes. More nodes = higher transaction throughput and increased decentralization. Sharding comes in many forms and Zilliqa uses network-, transaction- and computational sharding. Network sharding opens up the possibility of using transaction- and computational sharding on top. Zilliqa does not use state sharding for now. We’ll come back to this later.
 
Before we continue dissecting how Zilliqa achieves such from a technological standpoint it’s good to keep in mind that a blockchain being decentralised and secure and scalable is still one of the main hurdles in allowing widespread usage of decentralised networks. In my opinion this needs to be solved first before blockchains can get to the point where they can create and add large scale value. So I invite you to read the next section to grasp the underlying fundamentals. Because after all these premises need to be true otherwise there isn’t a fundamental case to be bullish on Zilliqa, right?
 
Down the rabbit hole
 
How have they achieved this? Let’s define the basics first: key players on Zilliqa are the users and the miners. A user is anybody who uses the blockchain to transfer funds or run smart contracts. Miners are the (shard) nodes in the network who run the consensus protocol and get rewarded for their service in Zillings (ZIL). The mining network is divided into several smaller networks called shards, which is also referred to as ‘network sharding’. Miners subsequently are randomly assigned to a shard by another set of miners called DS (Directory Service) nodes. The regular shards process transactions and the outputs of these shards are eventually combined by the DS shard as they reach consensus on the final state. More on how these DS shards reach consensus (via pBFT) will be explained later on.
 
The Zilliqa network produces two types of blocks: DS blocks and Tx blocks. One DS Block consists of 100 Tx Blocks. And as previously mentioned there are two types of nodes concerned with reaching consensus: shard nodes and DS nodes. Becoming a shard node or DS node is being defined by the result of a PoW cycle (Ethash) at the beginning of the DS Block. All candidate mining nodes compete with each other and run the PoW (Proof-of-Work) cycle for 60 seconds and the submissions achieving the highest difficulty will be allowed on the network. And to put it in perspective: the average difficulty for one DS node is ~ 2 Th/s equaling 2.000.000 Mh/s or 55 thousand+ GeForce GTX 1070 / 8 GB GPUs at 35.4 Mh/s. Each DS Block 10 new DS nodes are allowed. And a shard node needs to provide around 8.53 GH/s currently (around 240 GTX 1070s). Dual mining ETH/ETC and ZIL is possible and can be done via mining software such as Phoenix and Claymore. There are pools and if you have large amounts of hashing power (Ethash) available you could mine solo.
 
The PoW cycle of 60 seconds is a peak performance and acts as an entry ticket to the network. The entry ticket is called a sybil resistance mechanism and makes it incredibly hard for adversaries to spawn lots of identities and manipulate the network with these identities. And after every 100 Tx Blocks which corresponds to roughly 1,5 hour this PoW process repeats. In between these 1,5 hour, no PoW needs to be done meaning Zilliqa’s energy consumption to keep the network secure is low. For more detailed information on how mining works click here.
Okay, hats off to you. You have made it this far. Before we go any deeper down the rabbit hole we first must understand why Zilliqa goes through all of the above technicalities and understand a bit more what a blockchain on a more fundamental level is. Because the core of Zilliqa’s consensus protocol relies on the usage of pBFT (practical Byzantine Fault Tolerance) we need to know more about state machines and their function. Navigate to Viewblock, a Zilliqa block explorer, and just come back to this article. We will use this site to navigate through a few concepts.
 
We have established that Zilliqa is a public and distributed blockchain. Meaning that everyone with an internet connection can send ZILs, trigger smart contracts, etc. and there is no central authority who fully controls the network. Zilliqa and other public and distributed blockchains (like Bitcoin and Ethereum) can also be defined as state machines.
 
Taking the liberty of paraphrasing examples and definitions given by Samuel Brooks’ medium article, he describes the definition of a blockchain (like Zilliqa) as: “A peer-to-peer, append-only datastore that uses consensus to synchronize cryptographically-secure data”.
 
Next, he states that: "blockchains are fundamentally systems for managing valid state transitions”. For some more context, I recommend reading the whole medium article to get a better grasp of the definitions and understanding of state machines. Nevertheless, let’s try to simplify and compile it into a single paragraph. Take traffic lights as an example: all its states (red, amber, and green) are predefined, all possible outcomes are known and it doesn’t matter if you encounter the traffic light today or tomorrow. It will still behave the same. Managing the states of a traffic light can be done by triggering a sensor on the road or pushing a button resulting in one traffic lights’ state going from green to red (via amber) and another light from red to green.
 
With public blockchains like Zilliqa, this isn’t so straightforward and simple. It started with block #1 almost 1,5 years ago and every 45 seconds or so a new block linked to the previous block is being added. Resulting in a chain of blocks with transactions in it that everyone can verify from block #1 to the current #647.000+ block. The state is ever changing and the states it can find itself in are infinite. And while the traffic light might work together in tandem with various other traffic lights, it’s rather insignificant comparing it to a public blockchain. Because Zilliqa consists of 2400 nodes who need to work together to achieve consensus on what the latest valid state is while some of these nodes may have latency or broadcast issues, drop offline or are deliberately trying to attack the network, etc.
 
Now go back to the Viewblock page take a look at the amount of transaction, addresses, block and DS height and then hit refresh. Obviously as expected you see new incremented values on one or all parameters. And how did the Zilliqa blockchain manage to transition from a previous valid state to the latest valid state? By using pBFT to reach consensus on the latest valid state.
 
After having obtained the entry ticket, miners execute pBFT to reach consensus on the ever-changing state of the blockchain. pBFT requires a series of network communication between nodes, and as such there is no GPU involved (but CPU). Resulting in the total energy consumed to keep the blockchain secure, decentralized and scalable being low.
 
pBFT stands for practical Byzantine Fault Tolerance and is an optimization on the Byzantine Fault Tolerant algorithm. To quote Blockonomi: “In the context of distributed systems, Byzantine Fault Tolerance is the ability of a distributed computer network to function as desired and correctly reach a sufficient consensus despite malicious components (nodes) of the system failing or propagating incorrect information to other peers.” Zilliqa is such a distributed computer network and depends on the honesty of the nodes (shard and DS) to reach consensus and to continuously update the state with the latest block. If pBFT is a new term for you I can highly recommend the Blockonomi article.
 
The idea of pBFT was introduced in 1999 - one of the authors even won a Turing award for it - and it is well researched and applied in various blockchains and distributed systems nowadays. If you want more advanced information than the Blockonomi link provides click here. And if you’re in between Blockonomi and the University of Singapore read the Zilliqa Design Story Part 2 dating from October 2017.
Quoting from the Zilliqa tech whitepaper: “pBFT relies upon a correct leader (which is randomly selected) to begin each phase and proceed when the sufficient majority exists. In case the leader is byzantine it can stall the entire consensus protocol. To address this challenge, pBFT offers a view change protocol to replace the byzantine leader with another one.”
 
pBFT can tolerate ⅓ of the nodes being dishonest (offline counts as Byzantine = dishonest) and the consensus protocol will function without stalling or hiccups. Once there are more than ⅓ of dishonest nodes but no more than ⅔ the network will be stalled and a view change will be triggered to elect a new DS leader. Only when more than ⅔ of the nodes are dishonest (66%) double-spend attacks become possible.
 
If the network stalls no transactions can be processed and one has to wait until a new honest leader has been elected. When the mainnet was just launched and in its early phases, view changes happened regularly. As of today the last stalling of the network - and view change being triggered - was at the end of October 2019.
 
Another benefit of using pBFT for consensus besides low energy is the immediate finality it provides. Once your transaction is included in a block and the block is added to the chain it’s done. Lastly, take a look at this article where three types of finality are being defined: probabilistic, absolute and economic finality. Zilliqa falls under the absolute finality (just like Tendermint for example). Although lengthy already we skipped through some of the inner workings from Zilliqa’s consensus: read the Zilliqa Design Story Part 3 and you will be close to having a complete picture on it. Enough about PoW, sybil resistance mechanism, pBFT, etc. Another thing we haven’t looked at yet is the amount of decentralization.
 
Decentralisation
 
Currently, there are four shards, each one of them consisting of 600 nodes. 1 shard with 600 so-called DS nodes (Directory Service - they need to achieve a higher difficulty than shard nodes) and 1800 shard nodes of which 250 are shard guards (centralized nodes controlled by the team). The amount of shard guards has been steadily declining from 1200 in January 2019 to 250 as of May 2020. On the Viewblock statistics, you can see that many of the nodes are being located in the US but those are only the (CPU parts of the) shard nodes who perform pBFT. There is no data from where the PoW sources are coming. And when the Zilliqa blockchain starts reaching its transaction capacity limit, a network upgrade needs to be executed to lift the current cap of maximum 2400 nodes to allow more nodes and formation of more shards which will allow to network to keep on scaling according to demand.
Besides shard nodes there are also seed nodes. The main role of seed nodes is to serve as direct access points (for end-users and clients) to the core Zilliqa network that validates transactions. Seed nodes consolidate transaction requests and forward these to the lookup nodes (another type of nodes) for distribution to the shards in the network. Seed nodes also maintain the entire transaction history and the global state of the blockchain which is needed to provide services such as block explorers. Seed nodes in the Zilliqa network are comparable to Infura on Ethereum.
 
The seed nodes were first only operated by Zilliqa themselves, exchanges and Viewblock. O