CBSA BTA Certified Blockchain Solution Architect Question and Answers

BFT is notably implemented by Ripple (where validators are pre-selected by the Ripple foundation) and Stellar (where anyone can be a validator and trust is established by the community). BFT is advantageous because it presents scalability and low cost transactions, but like DPoS introduces a component of centralization.

Turing Complete – A language which lets developers solve any class of problem in existence given infinite time and resources Vs Turing Incomplete – Can’t solve all types of problems, such as problems with loops and iterations (Bitcoin)

2.0 Ethereum came after Bitcoin. Vitalik Buterin, one of the writers for Bitcoin Magazine that tried to popularize the technology in the early 2012. He witnessed first-hand the problems in the Bitcoin implementation like wasteful mining hardware, centralized mining community, and lack of network scalability. In 2013, the then 19 year old Vitalik described his vision for Ethereum by extending the concept of Bitcoin beyond just currency. He proposed a platform where developer community and entrepreneurs to build distributed application (Dapps) for the Blockchain network. He referred to this concept of trust beyond just currency as ‘smart contracts’ or even blockchain-based “decentralized autonomous organizations” (DAOs).

hyperledger is an open source collaborative effort created to advance cross-industry blockchain technologies. It is a global collaboration, hosted by The Linux Foundation, including leaders in finance, banking, Internet of Things, supply chains, manufacturing and Technology.

The EVM is basically a sandboxed virtual machine running on every single node. It is Turing complete and a transaction-based state machine. The nodes reach consensus by executing all transactions. Only the miner node gets the block reward, all other nodes are just checking if the miner was “honest”.

Hyperledger Composer is an open-source application development framework which simplifies the creation of Hyperledger Fabric blockchain applications, thus reducing the time and complexity of development. The tool aims at helping users to create blockchain applications based on Hyperledger Fabric without needing to know the low-level (Go Programming) details involved in blockchain networks.

Every account has a persistent key-value store mapping 256-bit words to 256-bit words called storage.

Business logic – something isn’t right according to business requirements Security – the code is vulnerable to some security exploits Regression – some code updates caused existing features to break Performance – the code is slow or some actions execute extra functions

Smart contracts generally are not legal contracts. However, its possible that a smart contract could be accepted as a legal contract but not normally. Read more about Smart contracts here

Asymmetric cryptography utilizes two different keys, a public key and a private to encrypt and decrypt a particular data. The use of one key cancels out the use of the other.

The main disadvantages are huge expenditures, “uselessness” of computations and 51 percent attack.

To write smart contracts there are a few different languages: Solidity, which is like JavaScript and has .sol as a file extension, Serpent, Python-like with extension .se, and a 3rd, LLL, based on Lisp. Serpent was popular a while back but Solidity is the most popular right now and more robust, so just use Solidity. You prefer Python? Use Solidity.

Secure Registry Services enables Secured Docker Registry of base Hyperledger images and custom images containing chaincodes.

Remember, that the block creation time is set to 10 minutes and this can never change. So after a fixed time of approximately 2 weeks or exactly 2016 blocks the difficulty is re-adjusted. Increase in difficulty means target decreases.

To write smart contracts there are a few different languages: Solidity, which is like JavaScript and has .sol as a file extension, Serpent, Python-like with extension .se, and a 3rd, LLL, based on Lisp. Serpent was popular a while back but Solidity is the most popular right now and more robust, so just use Solidity. You prefer Python? Use Solidity.