Hey all, I studied the lecture of professor @pelon about Blockchain EOS . I learned alot now I am doing my homework. ![Blockchain EOS.png](https://cdn.steemitimages.com/DQmfMBP1kT2r8utyEaP6LgFkhMK3veghNJHUETyWXWojB6V/Blockchain%20EOS.png) ^{Source:- https://www.canva.com/}

1.- Explain the Delegated Proof of Stake, DPoS algorithm.

--- ![image.png](https://cdn.steemitimages.com/DQmZVfLrNEqDU8geJDc3HRujdMRmXptpxNK5mrdQJqsZVZB/image.png) ^{SOURCE: https://www.developcoins.com/delegated-proof-of-stake-dpos} Delegated Participation is a consensus algorithm designed by Daniel Larimer in 2014. It was developed to solve the scalability problem in the blockchain network. As it becomes more and more popular in the cryptocurrency world, DPoS has become one of the alternative algorithms for proof of work (PoW). Many blockchain projects use DPoS as their licensed algorithm, including Cardano, Solana, Steem, Hive, OracleChain, EOS, etc. ![image.png](https://cdn.steemitimages.com/DQmYbDxTR2oL2ESDgnXQPiSLjSFbeDMuwPqN2hbZWXAJLP4/image.png) ^{SOURCE: https://blockonomi.com/practical-byzantine-fault-tolerance/} DPoS has an important feature called Byzantine Fault Tolerance (BFT). But what is BFT? In the final analysis, the Byzantine failure is a logical problem, and participants must agree on the same strategy so that the system does not collapse. However, some participants may disagree with this strategy, and the system must be responsible for establishing the elements so that these participants will not cause disaster. When it is possible for a system to build these elements, it is when it is granted Byzantine fault tolerance. The DPoS BFT is very positive because it can give users a lot of security on the public blockchain. **WORKING OF DPOS** ---

Voting

![image.png](https://cdn.steemitimages.com/DQmZRj1wg1oKGAqfRzS5uCs6giCwMDXAogMgephgPKqc7y4/image.png) In the DPoS consensus, users can vote directly, or they can allocate their voting rights to other entities to vote on their behalf. The selected witness is responsible for creating the block by verifying the transaction. If they verify and sign all transactions in a block, they will receive a reward, which is usually shared with those who voted for the witnesses. If the witness cannot verify all transactions within a given time, the lock is lost, all transactions are not verified, and no reward will be assigned to the witness. The reward is added to the reward of the next witness who verifies the lock. These transactions are collected by the next witness, and the block is called stolen. The votes are proportional to the turnout of each voter. Users do not need a lot of participation to enter the top witnesses. On the contrary, the voting of users with a large number of rights can promote users with relatively small rights to the highest level of witnesses.

Witnesses

![image.png](https://cdn.steemitimages.com/DQmQ5nkEjwbnRgBSZo9k1E2terJkzUUstth2fN2CHQk4zGC/image.png) The number of top-level witnesses is limited to a certain range, generally within the range of 21101. These witnesses are responsible for verifying transactions and creating blocks. In return, they receive related fees. Witnesses can prevent specific transactions from being included in the block, but cannot change any transaction information, which makes them similar to miners in a proof-of-work blockchain. Voting is an ongoing process, and every witness at the top always runs the risk of being replaced by users who get more votes and are therefore considered more trustworthy. As the number of witness applicants increases and competition intensifies, reputation becomes crucial for each witness to remain competitive. Witnesses are under control for threats of loss of income, confinement rights and reputation scores. Witnesses must block some of their actions, and if they act maliciously or attempt to attack the blockchain, they will be confiscated. A round of N block producers / tokens on the DPoS blockchain follows the following circular sequence: 1) N block producers are selected from the pool of candidate tokens. 2) The k-th block producer signs the k-th block until k = N. 3) A block is voted by (2/3 + 1) block producers.

Delegates

![image.png](https://cdn.steemitimages.com/DQmZxdBHzpUjYbJW7qRtwEBUfydXJ6pyf2ftnJvkUrdAgB4/image.png) ^{SOURCE: https://images.app.goo.gl/MJ3MUFv4fyfVr8ch7} Users of the DPoS system also vote for a group of representatives to oversee the governance of the blockchain. They do not participate in the control of transactions. The representative may propose to change the size of the block or, in exchange for verifying the block, the amount to be paid by the witness. Once the representatives propose such changes, the blockchain users will vote to decide whether to adopt them.

Block validators

The block validator in DPoS refers to a full node that verifies whether the block created by the token follows the consensus rules. Any user can run the block validator and verify the network. There is no incentive to become a block validator. **ADVANTAGES AND DISADVANTAGES** ADVANTAGES | DISADVANTAGES ------------ | ------------- DPoS blockchain can well prevent double spending. As users/nodes require less participation|The effective operation and decision-making of the network requires representatives to be informed and to appoint honest witnesses. DPoS is more democratic and financially inclusive. Due to the low barrier to entry| A limited number of tokens can lead to the centralization of the network. DPoS provides more decentralization because more people participate in consensus| DPoS blockchain is susceptible to the weighted voting problem. Users with a low level of participation can refuse to participate in the vote after they consider their vote to be insignificant. DPoS does not require a lot of electricity to run the network, making it more sustainable| DPoS transactions do not depend on the computing power required to run the network, so they are more scalable|

2.- Explain What are Ricardian contracts on the EOS Blockchain?

Like many other concepts on the blockchain, the Ricardo contract is not a modern idea. However, they are being applied to the blockchain to improve its operation. Created by Ian Grigg, a pioneer in financial cryptography in the 1990s, this cryptographer and programmer designed it to be able to run it in a payment system called "Ricardo". The system is named after David Ricardo, an influential person in the economy at the time. Ricardo contracts are digital contracts that establish rules that related parties (users) must abide by and use cryptographic technology to verify and sign. These contracts can be read by humans and software because it has the ability to use human and computer languages. In other words, the Ricardo contract obtains information from a legal document and converts it to a format that can be run on a computer. Due to cryptography, the document reaches a very high level of security. The Ricardo contract connects digitization to the real world through the use of hash functions. **STELLAR** ![image.png](https://cdn.steemitimages.com/DQmRETz2Kcb2AhHYNMYpscHNjRXZo27jQDpC29zxoKf4Nq8/image.png) ^{SOURCE: https://images.app.goo.gl/SgaNaSxos1gzhm5q9} Stellar or Stellar Lumens is an open source decentralized protocol for low-cost digital currency transfer of medium of exchange, which may realize cross-border transactions between any currency pairs. The Stellar agreement was endorsed by the Stellar Development Foundation, a non-profit company in Delaware, while the organization doesn't enjoy IRS tax exempt status. The server runs the software implementation of this protocol and uses the web to attach and communicate with other Stellar servers. Each server stores a ledger for all accounts on the network. the three nodes are operated by the Stellar Development Foundation and 21 other organizations, providing a complete of 66 verification nodes. Transactions between accounts don't occur through mining, but through a consensus process between quorum accounts. the present network fee is 100, which is similar to 0.00001 XLM or 1/10,000th of a penny. **EOSIO** ![image.png](https://cdn.steemitimages.com/DQmVG2EcnKcebDVFUeNJm1CR32hiLsiT5BUVnreb576KqJF/image.png) ^{SOURCE: https://images.app.goo.gl/cWfDBj3g74sW7WRi7} EOSIO is the next-generation open source blockchain protocol with industry-leading transaction speed and flexible practicality. Block.One was founded in 2017 by Dan Larimer and Brenden Blumer as a private company that developed the EOSIO protocol. Larimer is a well-known brand among blockchain developers. In addition to EOSIO, he also designed the first decentralized exchange BitShares and the first encrypted social media network Steemit. The first is that EOSIO programmers can use WebAssembly languages such as C ++, Java, and Python to develop dapps instead of new, project-specific programming languages.

3. Explore the official EOSREX interface (eosauthority.com). Show screenshots.

--- Firstly we have to search eosauthority.com on google and here we can see the prices and many more details of EOS from here we can start exploring the things. ![image.png](https://cdn.steemitimages.com/DQmPkxdA43hwMbSL68qxTsy7zFbmQcwEUgACaGzTH37jqh3/image.png) Now click on the globe icon on above right corner and select your language my preferred language as English so I select English. ![image.png](https://cdn.steemitimages.com/DQmYTxRraNRHfEkujd5eqvZdL4r13v8ohNk7ZnXS32oCxDm/image.png) Then on click on dropdown option against EOS we can get many option like IOS BOS Telos wax. ![image.png](https://cdn.steemitimages.com/DQmUWBQxucm17GyrxEMFM8os1TioaxdETr8rC69qBBcu2D2/image.png) In EOS there are many options like wallet events tools dashboard and much more I highlighted on the screen shot down now let's explore one of them. ![image.png](https://cdn.steemitimages.com/DQmUyWpH27N7mttbdNjVVTcZm9128g4gWq9xYTinGoYzBm3/image.png) We clicked on wallet button now in wallet button we have options like add account send total number of USD used in a EOS BOS TELOS wax and price chart also there are many options like yearwise monthwise weekwise daywise. ![image.png](https://cdn.steemitimages.com/DQmePFfJin3GXxf7iZgpwj4KpaZTCJMbsQCAC4uKwTwJDSQ/image.png) Now let let explore events while taking on events we have options like add event Mai event makeup filter of events and total number of online events running. ![image.png](https://cdn.steemitimages.com/DQmQSLecR3pXWGZG7ttGLsTJyzEUn3tfvnPGsEgoPQMjcXB/image.png) Now let explore tools option while on tools we get total available 29 tools including all social media accounts BP information and voting information. ![image.png](https://cdn.steemitimages.com/DQmRFrAiRbXAUjvd6kvrtePhD3pzMTB7HXRgXMEogCcxXvn/image.png) Now when we switch to dashboard we have same option like wallet in dashboard also. ![image.png](https://cdn.steemitimages.com/DQmZHeBcu4fFxikNYwSgP5ZWKy2idUPEDaquppLT2spxrFc/image.png) Then we explore Wallet and we get options as we got above. ![image.png](https://cdn.steemitimages.com/DQmaa1FNqBF6MVAhTUnTiA7LLe4LnKboDjwQkABf516XsdM/image.png) Then on REX we have option like add account send and many on REX and analyse option. ![image.png](https://cdn.steemitimages.com/DQmexxpm5kNdXzS1cPNiJGpBRKD2k9UemnWAkMZP4KtDMmd/image.png) In power of we get get power option and analyse account option as previous. ![image.png](https://cdn.steemitimages.com/DQmVryTEe4CyFBdFwCtu4dKG5DqUEypQZTpv48vmquo4f8c/image.png) Manage CPU and RAM hare we can see how much RAM is you is in use and how CPU can balance the instake. ![image.png](https://cdn.steemitimages.com/DQmeBgWtFe434egmyPLyaDijPfXvZsXT6DpVFwMPjx4LxJK/image.png) Manage keys in this option we can see basic advance and link authority vacation there are many keys like only active ki owner ki available we can update our keys from here ![image.png](https://cdn.steemitimages.com/DQmWiqdaWkkwWMQ116sRB1tdgX29LGM9BAUWtaN4uBS9bSE/image.png) Now in vote section we can see produces proxies and polls option and we can vote through our opinion. ![image.png](https://cdn.steemitimages.com/DQmQWsNW9qKrLeGRzN1MsvDwyf4r76Zzx3qto8RjBHweiq2/image.png) Create account is a simple option to create new account to transfer simply on EOS. ![image.png](https://cdn.steemitimages.com/DQmeDcmaqn1Cughiqzn9PFJfki3dZgQDWy59h2uesR5huVC/image.png) Now on bid name we can see the bidding option who is the person who is bidding or who is the person have sold the bid date hybrid highest price and time left for the particular bit everything is shown in this section of bid name. ![image.png](https://cdn.steemitimages.com/DQmZLzKv4hZA5Bzav5qvnrwKqLVZSqMyRATs2pxrdr5dsv1/image.png) ![image.png](https://cdn.steemitimages.com/DQmSiY5d5FKhirMynTQRgYnmw62kvJ4wzYXQwGgABqA9ZuA/image.png) Now in trade your token we can see token name buying selling option limit option and delisted option here. ![image.png](https://cdn.steemitimages.com/DQmVn2BF335Y2LL2VgsFBonKr5ToTuJr7xL52U5vYJ5vrnK/image.png) Now there are more option like voters ram usage cpu usage total eos wallets take an stake and many more. ![image.png](https://cdn.steemitimages.com/DQmUSFVhbXG9M5F5k9QwViA6ShwVekFvqz8yy5cayZxnkkU/image.png) In menu option we can see blocked producer chain alert trading alert proxies transaction recent book producer accounts market cap name bids multi science we can see all of the thing in one menu option. ![image.png](https://cdn.steemitimages.com/DQmWejVNHhGCqo3dX3zM3q4qpJch2KgnkvebgHa8WmYJkG1/image.png) ![image.png](https://cdn.steemitimages.com/DQmbYeyPAyCpB84VmAdE1t7VetzdsW6QhK5xkj93N7EMPcK/image.png) ![image.png](https://cdn.steemitimages.com/DQmZLf7jJ3BryQhuzMjN8TXov8iGgt1GZUYTKNwjdQNNyeh/image.png) And at the end we can see the partners who who are involved in this authority here. ![image.png](https://cdn.steemitimages.com/DQmaDUKSPTRLRfGRDdWekHSkBE23x1zUvdanUM9soqrCm9F/image.png)

4.- Download the Sqrl wallet, explore and explain how to obtain CPU, RAM and Network. Show screenshot.

--- When we visit on https://sqrlwallet.io/ the interface is like this. Select your option of windows , iOS, Linux. ![image.png](https://cdn.steemitimages.com/DQmNjZkZRSb6up18JkiGv4QMCSiosUuP2z7nQNAHiMSDtEg/image.png) Then on display page select only for my PC and click on next. ![image.png](https://cdn.steemitimages.com/DQmZQ8JkzAErDaB7bsVFGcp2cPsQzdEAtDLWKyzf2Kzwmkm/image.png) Now select the location you want to install the wallet and click on install. ![image.png](https://cdn.steemitimages.com/DQmTqjcpGKEf9BUmzm5JGkTefcgfpMq63NMqVkdZywYUiqx/image.png) Then there is a highlighted step one hair you have to connect to the server. ![image.png](https://cdn.steemitimages.com/DQmYvcF8wY3iAtxetKXvJVVJfZfMxL4sqJ18jjYFEX5eVZf/image.png) There are two option important existing account or connect to new account and click on connect to new account. ![image.png](https://cdn.steemitimages.com/DQmag8JfLFzC3bzLYAhfCZEAzHV7ZubBa7hk2W3MXK6jWbM/image.png) Silver account details and after that you will get a error of username for you have to keep your username apart your name like animation 321 is my username. ![image.png](https://cdn.steemitimages.com/DQmRX1koijXxsfZ4fzCggAsDhPJXaEy51eDSb7YFk51m1sd/image.png) Copy all the keys and save them and click next. ![image.png](https://cdn.steemitimages.com/DQmYZ9Yz8d7TXXhcvKWfyrymxietXpxHzHnJzSpQvX1Bbmr/image.png) Now click on create my account here you will see an issue related to account creation then in next step we have to visit a website. ![image.png](https://cdn.steemitimages.com/DQmTF381cxKFg1LPCvQr6dXi5i9UgtivhF1H7fMNHM5ZKPA/image.png) Visit on telos click on start new https://www.telos.net/. ![image.png](https://cdn.steemitimages.com/DQmZii7fNjqYxZeTiw5d5uF1dXL7o8qxLS9myABgLWFR6Hs/image.png) Now click on create new account. ![image.png](https://cdn.steemitimages.com/DQmToxFcqJWNr1FPXct1Qi8emaXpUgBLQAHpBcatbR1Mo4c/image.png) Enter your username you kept in previous wallet and copy the keys from here and continue. ![image.png](https://cdn.steemitimages.com/DQma1SURuUDAFncFpQTZdmxxx5S668JyvXVzPb1mtKR8pPR/image.png) In step 2Now click on select account and move further. ![image.png](https://cdn.steemitimages.com/DQmYrGGQqH18J2hQBox9vjE1PVqgCfYW9c8ku78pygNAKjz/image.png) Paste the keys you copied before in SQL wallet this is step 3. ![image.png](https://cdn.steemitimages.com/DQmR4bNdD86FszDmD8eEhT1JADBzsJHfcM6UJPPuxvWvuNU/image.png) In step 4 create a password for your wallet on your own choice and save next. ![image.png](https://cdn.steemitimages.com/DQmb1oZKasYByWfDjjpu8CyphE1pFjuUwHUNgcfsqvjhV5G/image.png) Confirm the password of local wallet and proceed next. ![image.png](https://cdn.steemitimages.com/DQmTi6Y5kFTcU9W4Ugxo1dnezWLwZgb1uXoTQxb5VdLM6Qr/image.png) There are some terms and condition accept the terms and condition and go next ![image.png](https://cdn.steemitimages.com/DQmaBcvLDhnMetmaxdNFYiGcdzYCm3m3E6Xo418jeET6AoD/image.png) Here's the wallet is created and the wallet interface is like this. ![image.png](https://cdn.steemitimages.com/DQmRt52u6ugNaQgYpSds88d5gNFPUYmKBVnmm4D2j7L17mN/image.png) Now click on governance you will get some options as shown below. ![image.png](https://cdn.steemitimages.com/DQmaL5BMJz6PGjvEB8GtrNFDjmJ8zuxqPhGzs5jC7L2vQQ8/image.png) Now click on t-Rex you will get some option related to deposit land earnings etc. ![image.png](https://cdn.steemitimages.com/DQmRNmEU5SNXy4wVyeNKkDLSGcmbeUDbJRhhz6Z2wspM9Q5/image.png) In tools options we can see all the tools ewlated to wallet. ![image.png](https://cdn.steemitimages.com/DQmX1sMTVxwyUAvvSp5GZ8iL8mpjBLmZsseLfqxrgRwWjs9/image.png) Now in wallet option there is three main option like buy and sell, send recieve, advance. ![image.png](https://cdn.steemitimages.com/DQmWYFCY8QfjwtACz7zq84bfZRBrrMkfvnNKzR8kATXa7Xm/image.png)

BUY CPU

![image.png](https://cdn.steemitimages.com/DQmcLRzhc4Q6yfFY9a2yRc9GPQDVLjmQGHabf48WSdXNtLi/image.png) ![image.png](https://cdn.steemitimages.com/DQmYEje7QpuU7SUnoBeoDVYva2ZY7ySWkZPnGfzVo8X1sqv/image.png) ![image.png](https://cdn.steemitimages.com/DQmcgy5vZ7tQDrMTkE6cxCXna5Guq9G7haK1p6eFTRSZesd/image.png)

BUY RAM

![image.png](https://cdn.steemitimages.com/DQmYQxuHKa3qepkm7BX25cr72Zm4HG6NKrDbsFgCsue8oaS/image.png) ![image.png](https://cdn.steemitimages.com/DQmb4FthW74PXy4qU5RjuThYehBkzrenPxUJCwDKL69MDxQ/image.png)

NETWORK

![image.png](https://cdn.steemitimages.com/DQmPkjrwSKxwYx2vwEaoarvCeQpN1GC3j1dw9QXjTeNnte5/image.png)

Show the price of the REX token. And explain what it is used for?

--- REX tokens are tokens used in the EOSREX platform, and their function is to act as an incentive token for users who contribute resources (EOS, RED, CPU and RAM) to the ecosystem. This token was proposed by Dan Larimer in August 2018. This token has a 1:1 relationship with EOS tokens. The main difference is that it cannot be transferred between users, which is possible on EOS. The token can only be sold 4 days after the purchase. This feature is given by the smart contract, and we will be able to use it to obtain rewards paid in EOS tokens. Another condition of the REX token is that users who want to obtain it must first vote for a proxy or at least 21 tokens to generate blocks. ![image.png](https://cdn.steemitimages.com/DQmV5sMqVnx1DcDRVU5EtNd3PqYxxLJ1odJkBzaJB5gewQ3/image.png) **Price REX/EOS = 0.0001 EOS**

CONCLUSION

Over the years, the Delegated Proof of Stake (DPoS) consensus algorithm has become one of the most centralized networks because community users are in full control, rather than external entities. This is a network that will never stop under any circumstances, because users can change tokens that are not working well through the voting process at any time, making DPoS a safe, fast, scalable and environmentally friendly algorithm. EOS is a fast and secure platform that has gained a significant position in the world of cryptocurrencies over the years and has become a cryptocurrency with enormous market value. Its scalability, speed and low cost are important factors. that motivate investors to trust it. ---- THANK YOU