From 673151559be9b042fdf28e4a466a91b51cb123f4 Mon Sep 17 00:00:00 2001 From: nathalie-ckc Date: Mon, 17 Sep 2018 18:08:00 -0700 Subject: [PATCH 1/2] Chapter 1 improvements (#89) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Not doing Point 1 of Github issue 89, as stated in the issue 89 discussion. Point 2: Remove video on DLT vs. Blockchain ============================================= Remove the video, which confused students. See Discussion forum post: https://courses.edx.org/courses/course-v1:LinuxFoundationX+LFS171x+3T2017/discussion/forum/i4x-LinuxFoundationX-LFS171x-course-3T_2017/threads/5a78c95684452a081800089c. Extend explanation that Blockchain is just a type of DLT by mentioning 2 other types of DLTs. Point 3, Modified Point 4, Add missing link ================================================ Distributed Ledger Technology (DLT) > Blockchains (Continued) 3. Definition of block shouldn’t be split up with mention of bitcoin concepts in between. I put the bitcoin example after block is explained, for better concept flow. 4. Nonce relates to the Bitcoin example, so indicate that this list of 4 pieces of metadata refer to the Bitcoin example (which continues with the Merkle Tree section in the next slide). Bonus: "or a brief history of blockchain technology, please click here." was missing the link "here". Added it. Point 5: Remove conceptual speed bump ====================================== Distributed Ledger Technology (DLT) > Blockchains (Continued): I propose to mention that Merkle tree root will be defined on the next page, to remove a brain speed bump for students who don't know what a Merkle tree is. Signed-off-by: nathalie-ckc --- .../docs/discovering-blockchain-technologies.md | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/LFS171x/docs/discovering-blockchain-technologies.md b/LFS171x/docs/discovering-blockchain-technologies.md index 05a60b89..726e283f 100644 --- a/LFS171x/docs/discovering-blockchain-technologies.md +++ b/LFS171x/docs/discovering-blockchain-technologies.md @@ -8,7 +8,6 @@ - [Distributed Ledger Technology (DLT)](#distributed-ledger-technology-dlt) - [Video: Blockchain Technology (Robert Schwentker)](#video-blockchain-technology-robert-schwentker) - [Blockchains](#blockchains) - - [Video: The Difference between DLT and Blockchains (Brian Behlendorf)](#video-the-difference-between-dlt-and-blockchains-brian-behlendorf) - [Blockchains (Continued)](#blockchains-continued) - [Merkle Tree](#merkle-tree) - [Video: What Is a Blockchain? (Dave Huseby)](#video-what-is-a-blockchain-dave-huseby) @@ -123,22 +122,22 @@ According to [hyperledger.org](https://www.hyperledger.org), **Consensus** refers to a system of ensuring that parties agree to a certain state of the system as the true state. -## Video: The Difference between DLT and Blockchains (Brian Behlendorf) - -[![The Difference between DLT and Blockchains (Brian Behlendorf)](../images/video-image.png)](https://youtu.be/02IAHzvCh34) - ## Blockchains (Continued) -**Blockchain** is a specific form or subset of distributed ledger technologies, which constructs a chronological chain of blocks, hence the name 'block-chain'. A **block** refers to a set of transactions that are bundled together and added to the chain at the same time. In the Bitcoin blockchain, the miner nodes bundle unconfirmed and valid transactions into a block. Each block contains a given number of transactions. In the Bitcoin network, miners must solve a cryptographic challenge to propose the next block. This process is known as '**proof of work**', and requires significant computing power. We shall discuss proof of work in more detail in the Consensus Algorithms section. For a brief history of blockchain technology, please click here. +**Blockchain** is a specific form or subset of distributed ledger technologies (DLTs), which constructs a chronological chain of blocks, hence the name 'block-chain'. Examples of other DLTs are tangle and hashgraph. + +A **block** refers to a set of transactions that are bundled together and added to the chain at the same time. Timestamping is another key feature of blockchain technology. Each block is timestamped, with each new block referring to the previous block. Combined with **cryptographic hashes**, this timestamped chain of blocks provides an immutable record of all transactions in the network, from the very first (or genesis) block. -A block commonly consists of four pieces of metadata: +In the Bitcoin blockchain, the miner nodes bundle unconfirmed and valid transactions into a block. Each block contains a given number of transactions. In the Bitcoin network, miners must solve a cryptographic challenge to propose the next block. This process is known as '**proof of work**', and requires significant computing power. We shall discuss proof of work in more detail in the Consensus Algorithms section. For a brief history of blockchain technology, please click [here](https://hbr.org/2017/02/a-brief-history-of-blockchain). + +A Bitcoin block consists of four pieces of metadata: * The reference to the previous block * The proof of work, also known as a nonce * The timestamp -* The Merkle tree root for the transactions included in this block. +* The Merkle tree root for the transactions included in this block. (Merkle tree is explained next) ## Merkle Tree From 0a7daa37dbead4d1db83d8fd5f772a4012bc67ce Mon Sep 17 00:00:00 2001 From: nathalie-ckc Date: Tue, 18 Sep 2018 17:01:12 -0700 Subject: [PATCH 2/2] Address review feedback for PR#98 Replaced examples tangle & hashgraph with the examples of DLTs that are covered later in the chapter. Signed-off-by: nathalie-ckc --- LFS171x/docs/discovering-blockchain-technologies.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/LFS171x/docs/discovering-blockchain-technologies.md b/LFS171x/docs/discovering-blockchain-technologies.md index 726e283f..d44decef 100644 --- a/LFS171x/docs/discovering-blockchain-technologies.md +++ b/LFS171x/docs/discovering-blockchain-technologies.md @@ -124,7 +124,7 @@ According to [hyperledger.org](https://www.hyperledger.org), ## Blockchains (Continued) -**Blockchain** is a specific form or subset of distributed ledger technologies (DLTs), which constructs a chronological chain of blocks, hence the name 'block-chain'. Examples of other DLTs are tangle and hashgraph. +**Blockchain** is a specific form or subset of distributed ledger technologies (DLTs), which constructs a chronological chain of blocks, hence the name 'block-chain'. Examples of other DLTs are Chain Core, Corda, Quorum, and IOTA. They will be covered later in this chapter. A **block** refers to a set of transactions that are bundled together and added to the chain at the same time.