BlockStamp Whitepaper

Monday, January 13, 2020
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Whitepaper Version 3, BlockStamp, 30th January 2019

Summary 3 What is BlockStamp 3 Document and signature storage 3 BlockStamp Games 4 DNS 5 Future applications 5 BlockStamp investment 5 BlockStamp Team 6 BlockStamp Roadmap 8 Technology 9 BST Blockchain characteristics 9 Document and signature storage 10 Usage 10 Gaming​ center 12 Random Number Generation 12 Jackpot concept 13 Roulette betting model 13 Lottery betting model 15 Mechanisms for your own game 16 Bet verification 17 Block hash/number 17 Transaction hash 22 Wallet address 23 Mining and poles 26 Installation 26 Mining constraints 26 The approach to casino’s profitability 27 DNS 27 Description 27 Usage 28 Atomic transaction 30 Workflow example 36 Desktop application & Wallet 38 Value transfer 38 Gaming 39 Data 39 Appendix 1 - bet types, syntax, and numbers 40 2 ​

Summary This documents describes the current status of the BlockStamp project, its functionalities and potential. The document will be constantly updated as the BlockStamp will be evolving. The document is maintained by the BlockStamp and its latest version will always be available on the project’s ​website​. 1. What is BlockStamp BlockStamp (BST) is a new digital currency intended to store user data in blockchain. It is based on Bitcoins peer-to-peer technology to operate with no central authority. The goal was to create a new fast and effective blockchain that could be used for trusted timestamping of documents. Currently, BlockStamp blockchain is used as the core of an online gaming platform. Future uses will cover timestamping dedicated for banking purposes, DNS and more. BlockStamp Games is an example of an implementation of randomized transactions provided by the BlockStamp blockchain. The blockchain offers the possibility to obtain fair, untempered randomness that can be used in many applications such as e-gaming. 1.1. Document and signature storage Sensitivity of banking transactions requires a very solid, hacking-proof, and secure system to store the data. BlockStamp blockchain is designed for this very purpose and can offer tamper-proof timestamping of banking transactions. 3 ​

This can include but is not limited to: ● Money transfers ● Stock exchange prices ● Bonds ● Debentures ● Bank loans ● Notes payable ● Other debts units This functionality is under development currently and will be made available shortly. 1.2. BlockStamp Games The whole concept was to facilitate e-gaming in a completely new form, where there is no casino side, no house edge, and all the transactions can be verified by the players. There were many attempts in order to create such a platform, however most of them failed during implementation, while some are still suffering from long implementation processes. The majority of those were ICOs, which after the initial fundraising, failed to produce the actual product. We took a completely different approach and decided to build our own currency as part of the project instead of raising funds for building online e-gaming sites. Our goal was to build the whole new platform which would be able to host players and to provide randomness with 0% edges and minimal fees at the same time providing transparency of all the transactions. Hence, we decided to develop a new currency which blockchain would be used for the fairness purposes. BlockStamp blockchain levels all issues with provably fairness, transparency, or any kind of tampering with the game results. 4 ​

Current cryptocurrency casino market is still in its infancy, while its older brother does not provide any good example. The most common issues are: ● Lack of transparency of transactions ● High probability of tampering with game results (centralised infrastructure with no access from the outside of the casino) ● High fees related with betting and winning ● Extended withdrawal times and high withdrawal fees. ● Progressive jackpot ● No possibility to host one’s own game ● Overall casinos’ profit orientation BlockStamp Games gets rid of all that and aims at educating people about gambling. The goal is to fight with gambling misconceptions by providing a platform that demonstrates that chance can not be controlled. The player can test different strategies and learn that the chance to win significant amounts is small even in a casino that does not take any fees. The player can run the test with demo coins that can be restored indefinitely and with crypto coins that can represent some value. In the second case the player can assess how an increase in the value of risked tokens affects the emotions during the game. When playing with demo coins the player is warned about potential risk of a gambling disorder when the balance drops below 90% of the starting balance. 1.3. DNS The concept is based on the fact that more and more domains are being watched and blocked, against the will of the users. Peer-to-peer DNS prevents this kind of situations. This functionality is under development and will be made available shortly. 1.4. Future applications Given that BlockStamp can be perceived as a solid timestamping device, its applications can only be limited by its users’ imagination and requirements, but not by its functionality. A set of flexible procedures will be issued which will make purpose oriented timestamping possible. This document will be updated accordingly. 5 ​

1.5. BlockStamp investment BlockStamp currency is deemed to be a profitable investment option due to the following aspects: ● The gambling market was estimated at 44.16 billion in 2016 and is expected to reach USD 81.71 billion by 2022 according to Business Wire (​https://www.businesswire.com/news/home/20170928005702/en/Glob al-Online-Gambling-Market-2017-2022---Research​). Those numbers take under account only the official gambling market, while the illegal is deemed to be somewhere between 80 and 380 billion USD. The popularity of online gambling is growing and so will the BST price. ● According to the C ​ oinMarketCap​, currencies’ prices are in general higher and much more stable compared with tokens. BST is bitcoin fork and is expected to be stable and well priced. The currency is already being mined and used, hence it will not join the ​Dead coin​ list. ● The wide applicability of the BlockStamp functionality will hook it on the market and provide a solid base for cooperation with well recognised brands, e.g. on the financial market. Although all investments have some degree of risk incorporated into them, the risk related with investing in BST has been diminished and is as low as possible on the crypto (and some fiat) investment market. Further information can be provided on a request basis, if required. 1.6. BlockStamp Team Jędrzej Sadowski - CEO Jędrzej Sadowski is the CEO of the BlockStamp Foundation. He has 15 years of experience in legislative work aimed at liberalization of the business environment in Poland. Since a few years, he is actively involved in research on the legal basis for cryptocurrencies at the Institute of Law Studies of the Polish Academy of Science. 6 ​

Leszek Rychlewski - Founder MD and a serial entrepreneur who started BioInfoBank Institute - an institution known for many inventions in the bioinformatics field. Since 2012 interested in blockchain - his team created ASIC miners which were accountable for 50% of bitcoin mining power in 2013. In recent years he was working on blockchain solutions such as micropayment system called Enterprise Service Chain. Leszek earned his Ph.D. at the Humboldt-Universität zu Berlin. Krzysztof Kuchta - CTO Krzysztof is an expert in developing solutions for efficiency and productivity. He has broad experience in software development as well as in data analysis. He is the founder of Spotree, a company that has build a tool for detection and blocking unauthorized access to the company’s critical resources. Krzysztof graduated from the Inter-Faculty Interdisciplinary Doctoral Studies in Natural Science and Mathematics University of Warsaw. He is the author of multiple publications in the bioinformatics field. Tomasz Słaboń - Blockchain Developer Having long and meaningful experience working with Nokia as a Software Engineer Tomasz is a valuable part of our Team. He earned his Master Degree in Computer Science at the Częstochowa University of Technology. 7 ​

Sławomir Możdżonek - Blockchain Developer He is not only a true blockchain veteran - in his career, he worked in projects related to microcontrollers, signal processing, DVB drivers, and many others. He participated in huge projects related to signal processing, data communication and networking in the radar devices. Earned his Ph.D. in Radiocommunication, designing a next generation TETRA. Stanisław Jankowski - Software Engineer He is a senior developer with 8 years of experience he gained while working on big web systems. His favorite programming languages are Python and Scala but he is also comfortable working with JavaScript, Java and Perl. Daniel Dumin - Product Designer Daniel is our UX magician. He knows exactly what great user experience means and this is why all our interfaces are so user-friendly. He started his career in IT then had a short affair with marketing only to come back to IT where his heart truly lies. He spent almost a decade on designing websites and web applications. 8 ​

Marcin Groszkiewicz - Front-End Developer Marcin is BlockStamp frontend developer. In the past, he was coding responsive layouts for magazines such as Forbes or Newsweek. He is also a crypto miner and active crypto trader. You can meet him at Crypto conferences, which he attends regularly. He quit online gambling disgusted, after finding out how ‘non-random’ casinos can be. As a secret, we can tell you that his client-side experiences with unfair roulette algorithms only motivate us more to make BlockStamp games radically fair. Jacek Omelan - Front-End Developer Jacek is also our frontend developer, making our ideas live. Before joining our team he was working on numerous projects such as the most popular navigation system for public transportation in Poland or Stepstone - one of the most successful online job board businesses today. 1.7. Blockstamp Roadmap Blockstamp team has a long term plan for project development. We focus on creating useful tools to protect all types of users data in secure blockchain ecosystem. Blockstamp is a working platform which is available to use right now. Nevertheless, we have the exact plan and resources to implement new practical solutions for our community. 9 ​

Cryptocurrency transfer April 2018 Near-tamper proof blockchain technology, hosting BlockStamp currency is now combined with 1 minute block time to ensure everything happens quickly and efficiently. BlockStamp online wallet - fully secure way to hold your BST February 2019 BlockStamp online wallet with major security improvements such as PBKDF2 to protect your password from brute force attack is a convenient and user-friendly way to protect and manage your funds. lockchain based e-gaming and education platform February 2019 Players can test different gambling strategies in a 0 house fee environment. Players can learn that chance can not be controlled. Check it out here: h ​ ttps://blockstamp.games/ Privacy network participants earn in BST February 2019 Hprox is a BlockStamp partner project allowing users to surf the internet 100% anonymously. Members can rent out their IP addresses to privacy seekers in exchange for BST. Check it out here: h ​ ttps://hprox.com/ 1 ​ 0

Coinpaprika crypto market cap site lists the BST February 2019 You can track all the most important data about the BST crypto coin such as its current price, exchange volume, and more. Check it out here: h ​ ttps://coinpaprika.com/coin/bst-blockstamp/ BST mining pool March 2019 You can join the BlockStamp mining pool via h ​ ttp://bsod.pw/​. The GPU and CPU miners' software is available at our github. Listing on CoinMarketCap April 2019 BST lists on the world’s favorite cryptocurrency market cap ranking site. Check it out here: h ​ ttps://coinmarketcap.com/currencies/blockstamp/ BlockStamp OpenBazaar Listing Explorer August 2019 The BlockStamp listing explorer offers a full view of OpenBazaar’s decentralized, commission-free marketplace. Sellers can boost their products’ search rankings by burning BST. Rooms at BlockStamp Games September 2019 BlockStamp Gamers can create and administer their own casino rooms for friends. 1 ​ 1

Blockchain data sealing via online wallet October 2019 Users can easily secure and authenticate their valuable data directly through the BlockStamp online wallet. BlockStamp Chat November 2019 A decentralized mobile and desktop messaging application focused on security and privacy. 2. Technology 2.1. BST Blockchain characteristics BST is hard fork from BTC blockchain and as such it share almost all characteristics of the original blockchain. The main difference of the BST chain being the hashing, as hashes of the blocks start with the most significant bit set to one (0x80000000....) instead of the original zero (0x00000000...). In terms of transactions recording, the BST blockchain is almost identical with BTC blockchain. As such, it will be used for timestamping of transaction documents. However, to make the timestamping faster and more efficient, the transaction size was increased to 1MB and block time was reduced to 1 minute. BST is minable currency with the number of BST increasing by an average of 500 000 BST each year. The rate of block creation is adjusted by Difficulty Adjustment Algorithm, which is similar to Bitcoin Cash - BCH. The number of BST generated per block equals 1 BST and is constant all over the time. Chaining the blocks, like with BTC blockchain, makes it impossible to modify each block without modifying all the subsequent blocks. This is due to the hash of previous block being included in the following block. Given that a 1 ​ 2

block’s hash is generated based on its content, the block’s content modifications would alter the hash and all subsequent blocks either. This characteristics of a blockchain is used for ensuring that no transactions, (as well as wins and loses in the gaming) would be tampered with. This is by far the most foolproof approach given the current technology. 2.2. Document and signature storage 2.2.1. Usage To store and retrieve data from the blockchain following RPC commands should be used: I. bst-cli storemessage which accepts data string as an argument and returns block hash, e.g. bst-cli storemessage "user data string" RETURN: c04878b7bf26def16ee689863943da91f9e7dcce77250e1ca8b63 90549356006 II. bst-cli retrievemessage ​which retrieves message from a particular block (accepts block hash as an argument and returns the data string contained by it, e.g. bst-cli retrievemessage c04878b7bf26def16ee689863943da91f9e7dcce77250e1ca8b63 90549356006 RETURN: " ​ user data string" III. bst-cli storesignature​which can store user’s digital signature into a transaction, retrieved from a file; it accepts path to the file as an argument and returns block hash, i.e. bst-cli storesignature /path/to/file/myfile RETURN: 0eec311afa6e8253c984d9bd57dadedd72848065160a093dc66a7 76388cfda13 IV. bst-cli storedata​which takes any data from a file and stores it in a block; it accepts path to the file as an argument and returns block hash, i.e. bst-cli storedata /path/to/file/myfile 1 ​ 3

RETURN: ad1e1c0736f366fdf6b2e9b63048c02a0aef83fdf4e705e78f89c 3e654fa3323 V. bst-cli retrievedata​which retrieves data from a block and returns it as a string; it accepts block hash as an argument and returns the data string contained by it, e.g.: bst-cli retrievedata ad1e1c0736f366fdf6b2e9b63048c02a0aef83fdf4e705e78f89c 3e654fa3323 RETURN: " ​ content of a myfile as a string" VI. bst-cli retrievedata​Same as above, only with two arguments (block hash and path to a file to which the command is suppose to store the data), it returns no output, e.g.: bst-cli retrievedata ad1e1c0736f366fdf6b2e9b63048c02a0aef83fdf4e705e78f89c 3e654fa3323 /path/to/file/outfile RETURN: (none) To check if data stored in blockchain match user data, the following RPC commands should be used: I. bst-cli checkdata​which retrieves data from a block, compares with the file provided as second argument and returns PASS or FAIL depending on the comparison result, e.g. bst-cli checkdata e.g.:ad1e1c0736f366fdf6b2e9b63048c02a0aef83fdf4e705e7 8f89c3e654fa3323 /path/to/file/myfile RETURN: P​ ASS II. bst-cli checkmessage​which retrieves data from a block, compares with the string provided as second argument and returns PASS or FAIL depending on the comparison result, e.g. bst-cli checkmessage c04878b7bf26def16ee689863943da91f9e7dcce77250e1ca8b63 90549356006 "user data string" RETURN: P ​ ASS 1 ​ 4

III. bst-cli checksignature​which retrieves signature from a block, compares with the file provided as second argument and returns PASS or FAIL depending on the comparison result, e.g. bst-cli checksignature 0eec311afa6e8253c984d9bd57dadedd72848065160a093dc66a7 76388cfda13 /path/to/file/myfile RETURN: P ​ ASS IV. bst-cli listtransactions​which retrieves transactions list from a block and returns it. In addition to the list, it also returns "datasize" field informing about the size of the data stored in the blockchain, e.g.: bst-cli listtransactions 0eec311afa6e8253c984d9bd57dadedd72848065160a093dc66a7 76388cfda13 2.3. Gaming center The idea behind the gaming center was to create a platform anyone could use. The design allows us to get rid of house (and house edge). The platform is an open source project, and is available to everyone on G ​ itHub​ for view and for use. Everyone who wishes so can download the code, and build one’s own node, which can then be used for mining and gaming. 2.3.1. Random Number Generation There are different approaches to the topic of random number generation, and the topic is also one of the most sensitive aspects of gaming. Everyone knows that randomness is the key to fair gaming. Old Fashioned central server online casinos were very often accused (not without a reason of course) of tampering with the random number generators or of having no randomness implemented at all. It is not very surprising, given the profit oriented approach of most, if not all, of the casinos. Having a solid random system is key to building a trustworthy online casino. As said, there are different approaches to the RNG, with Oracles being the most popular for ETH smart contract. Most of the random number generation approaches are deemed slow and ineffective. There is no truly random system in computing science, nevertheless some degree of randomness can be obtained. BlochStamp casino’s approach is to use the hash of the block containing bet transaction. This approach guarantees true randomness as no user can predict the hash of the block his/her transaction will be put into. 1 ​ 5

When accepted by pool, a bet is put into a block. The last 4 bytes word of block hash is divided modulo by the modulo argument (the actual bet) and the result is increased by 1. The result is then taken and compared with the bet, and the bet is a winning one if the numbers are equal. For example, let’s imagine that a user bets on roulette result to be 12. The bet is put into a transaction and the transaction is part of a freshly mined block. The hash of the block is then truncated to obtain only the last 4 bytes, decimalised, and divided modulo 36. The result of the equation is increased by 1. If the increased value is equal 12 then the bet is a winning one. 2.3.2. Jackpot concept By design, the jackpot MAX_PAYOFF is limited to 1024*1024 BST, i.e. 1 048 576 BST. The jackpot is set to this amount from the beginning. No losing bets are required to fill it in. It is also designed so that a win of the maximum amount does not reduce future rewards. The reward coins will simply be mined as part of the block containing the winning transaction. The design was possible due to probability of a win of such amount and some constraints on the actual betting. There are two rules around how transactions are chosen for blocks. The sum of input amounts (all bets) included in a given block will not be greater than 0.9 of a current block subsidy (i.e. 50BST at the moment), and the sum of payoffs/rewards for for a block will not be greater than the sum of the inputs and the subsidy. This prevents huge bets with lowest modulo (i.e. 2) that can cause the system to collapse. 2.3.3. Roulette betting model The BlockStamp roulette was designed to have 0% house edge, as there is no House betting with the players. Understandably, there is no 0 or 00 on the roulette. The numbers available for betting are 1-36. This adds up to the fairness of the gaming model, as the win on a single number is true 35:1. The transaction to make a bet and play is m​ akebet​. In order to make a bet, a user needs to choose a number or numbers and the sum of a bet. There are 13 types of bets: ● Straight (single number) with 35:1 ratio 1 ​ 6

● Split (two numbers) with 17:1 ratio ● Street (three numbers) with 11:1 ratio ● Corner (four numbers) with 9:1 ratio ● Line ( six numbers) with 6:1 ratio ● Column (twelve numbers) with 3:1 ratio ● Dozen (twelve numbers) with 3:1 ratio ● Low (eighteen numbers) with 1:1 ratio ● High (eighteen numbers) with 1:1 ratio ● Even (eighteen numbers) with 1:1 ratio ● Odd (eighteen numbers) with 1:1 ratio ● Red (eighteen numbers) with 1:1 ratio ● Black (eighteen numbers) with 1:1 ratio Details of the actual bet types are available in A ​ ppendix 1​ of this document. There can be more bets in one transaction than one. For example: makebet [email protected][email protected][email protected] Which is a compilation of three bets: ● No 3 with 0.1BST bet amount ● No 7,8,9 with 0.05BST bet amount ● High numbers with 0.7BST bet amount The details of the bet will be stored in op_return field in the transaction. In this case, it would look as follows: Op_return: [email protected][email protected][email protected] To make a bet a user should have total transaction input amount equal to sum of bet amounts plus fee. In this case: 0.1+0.05+0.7+0.000x BST. The fee is computed automatically inside makebet RPC and is the mirror of current BTC fee algorithm. This fee is a mining fee only, there are no other fees related with betting or winning. Calling makebet RPC returns transaction ids. Making bets has following limitation, by design: ● Maximum modulo argument (reward ratio) is 1024*1024*1024 ● Maximum payoff is 1024*1024 BST ● Minimum bet is 0.00000001BST Winnings are redeemed automatically. A block following the block containing the winning transaction, will contain a payout transaction. The winning will be transferred to the wallet used in the ​makebet​transaction. Before block 224940, the implementation included a g​ etbet​transaction that was designed to verify if a transaction was a winning or a lose and redeem 1 ​ 7

the reward to a wallet provided as the transaction’s parameter. Calling makebet RPC returns transaction id. This transaction ID was used then as an input to g ​ etbet​RPC, which accepted two arguments - transaction ID and an address where the reward should be sent. For example: getbet 123d6c76257605431b644b43472ee3666c4f27cc665ec8fc48c2551a88 f9906e 36TARZ3BhxUYaJcZ2EF5FCT32RnQPHSxYB Getbet​returned a transaction ID for a successfully redeemed wins or errors in case of loses. To properly redeem the win amount, Pay-To-Public-Key-Hash transaction keys must have matched. Please note that the transaction is obsolete and it no longer exists. It was replaced by the automated redeem system introduced by the hardfork in block 224940​. This applies also to the lottery and the mechanism for user’s own game described below. 2.3.4. Lottery betting model Lottery also utilises ​makebet​transaction with the same syntax. What makes lottery different is that the only bet type available is straight bet. Each makebet​can define one number or more as separate bets from 1 up to 2^30 with modulo set to maximum 2^30. Makebet RPC can accept more than one straight bet, up to 10 bets. The modulo operator defined is tantamount to the number of options we draw from. For example: makebet [email protected][email protected] 72 would put into a transaction a bet for No 2 and No 3 with different incentives (0.1BST and 0.05BST accordingly). Having modulo set to 72 means that the 4 bytes of hash of the block in which the transaction will be put, shall be divided modulo 72 (as if we drawn from 72 numbers from 1 to 72). If the result of the hash modulo 72 operation plus one is equal to any of the numbers user betten on, the transaction will be a winning one. All bets in one m ​ akebet ​RPC are subject to the same rules and same modulo defined in the m ​ akebet​. In this case reward ratio is equal modulo argument and the op_return field contains only reward ratio and consecutive straight bets, excluding bet name prefix (e.g. "straight"). For example, in case of the above bet op_return bet description would look as follows: op_return: [email protected][email protected] 1 ​ 8

If a bet is a losing one, all coins in the bet are sent to the op_return and ‘burnt’. Otherwise, the rewards are sent automatically to the bet wallet in the following block. 2.3.5. Mechanisms for your own game The BlockStamp platform can be treated as a hosting platform for user’s own game. M ​ akebet transaction is available for this option and works as it does in the lottery game. User’s own game rules determine the bets and modulo, where module is the reward ratio. For example, if dice is to be implemented, the bets should accept numbers from 1 to 6 and modulo should be set to 6. If two dices are to be rolled together, numbers would be from 2 to 12 and modulo should be set to 11. To avoid 0, the result of hash modulo operation is plused one and only after that it is compared with the number user betted on. So the makebet could look as follows: makebet [email protected][email protected] 11 This means that a user bets on double dice rolling 2 (1+1) with 0.1BST and 11 (5+6) with 0.05BST. Modulo is set to 11, and the block of the hash which would contain the bet would be divided by 11 and then added 1. As for the actual transaction syntax, it looks as follows. M​ akebet​transaction is signaled by 30’th bit in the transaction version field. Value 1 at this position (0x40000000) sets transaction type to m ​ akebet​transaction. Bets outputs occupies outputs beginning from index 0. Next to bets output, there is an op_return output containing the description of the bets included in the transaction. The op_return string begins with hexadecimal number defining a modulo argument (e.g. 0x24 for roulette, 0x48 for out lottery example, and 0xB for our double dice example), followed with user bets. The modulo argument is separated by underscore, bets are separated by plus. The last output field is reserved for change purpose, where change is transaction input minus bets amount minus fee, i.e.: prev_txs_outs_amount-Bet1_amount-Bet2_amount-Bet3_amount-. ..-fee In case then the transaction input is 50BST (which is the standard block reward), and 3 bets for 0.1BST, 0.05BST, and 0.7BST, and fee=0.0004 BST the change field would contain 49.1496 BST (50-0.1-0.05-0.7-0.0004 = 49.1496 BST). 1 ​ 9

If a bet is a losing one, all coins in the bet are sent to the op_return and ‘burnt’. Otherwise, the rewards are transferred automatically, as in roulette and lottery 2.3.6. Bet verification What one needs to know before doing the calculations is that block hash in which a transaction is put is our random number which is used for the actual draw (or roulette spin). Details are available on our g ​ ithub wiki​ and in this very document. It contains all the details on how it is ensured that there is no way anyone can predict the random numbers before making a bet. The procedure is pretty simple as all the necessary details can be found via BST explorer​. Data needed for the verification is either of the following: 1) Block hash/height 2) Transaction hash (your bet) 3) Wallet address 3.2.6.1. Block hash/number Block hash or block height can be put into the explorer search which can be found on the top left corner. A result of the search is a block with all the details. For example: https://explorer.blockstamp.info/block/8000000000023e663e322af14e8febec fa5047bf28158ac3a13e4a06db69b212 2 ​ 0

What can be found there are all block details, like block size and time, fees, amount transacted. Also the list of all transactions that were part of that block is available. The required bet transaction should be there too. It will contain all the details like wallet address, type of game (roulette, lottery), the bet details like bet type for roulette (e.g. a single number, corner, line) and a number plus pool/modulo for lottery. Pool/modulo is the number of options used to draw from, e.g. for a draw of 1 number out of 6 - 6 will be the modulo. 2 ​ 1

The transaction will also instantly show you if it was a win or a loss To do one’s own calculations the steps are as follows: - Take the last 8 characters of the block hash (which is our example is db69b212​) - Use an online tool to decimalise the numbers. We suggest https://www.rapidtables.com/convert/number/hex-to-decimal.html​ and it gives us 3 ​ 681137170​. - The decimalised value needs to be divided by the modulo, which for roulette is always 36 but for lottery (and this is the example used here) it is the defined pool of numbers. In our example, it is 1 ​ 374 2 ​ 2

For modulo operation, we recommend this calculator: https://www.miniwebtool.com/modulo-calculator​ The result of the operation is 1​ 84. - All results are increased by one in order to avoid zeros. So the actual result of the lottery game is ​185​. - Now you need to compare it with the number you betted on. In our example, they are equal. A roulette example would only differ at the point where the modulo operation comes in. To picture that, the following winning transaction and the block containing will be used: https://explorer.blockstamp.info/block/80000000000effc8960ec3254ed66668 a9a193c3b7d2ee859538bfc311d73245 https://explorer.blockstamp.info/tx/5080f81f77a8bf01834696de71a8d05f468 56c6db48b324a6b7dce89e4bbd043 2 ​ 3

The calculations are as follows: - The last 8 characters (​11d73245​) decimalised would make 2 ​ 99315781 - 299315781​ modulo 3 ​ 6​ (the default roulette modulo) is 9 ​ - 9​ plus 1 is 1 ​ 0​ so the actual result of the roulette round is 1 ​ 0​. - Now, comparing it with the bet which was CORNER (7, 8, 10, 11) we can see that 1 ​ 0 ​is one of the betted numbers. Hence, the transaction is a win Alternatively, having block hash, one can check the following block in order to see all reward transaction details. For example, block 229353 (​https://explorer.blockstamp.info/block/8000000000001a2b1cd5ba03ef55c31 c50f2cb5e62c0353234bf421297cdd859​) contains: 2 ​ 4

And the following block 229354 (​https://explorer.blockstamp.info/block/800000000000020398b7a3b0d94866 2d4f520b821951c53f0fd31a2d8fba6906​) contains the following transaction: 3.2.6.2. Transaction hash If only transaction hash is available, the verification instructions are as follows: - Go to the ​explorer a​ nd search for the transaction hash. You will be shown the transaction details. - Find the block details is to click on the advanced properties of a transaction and check which block was it part of. The link there will open the block details for you. 2 ​ 5

- Having the block’s hash, you can start the calculations. Just follow the above instruction and you will verify your bet. 3.2.6.3. Wallet address If all info available is the wallet address, the verification is also possible. The above lottery win example will be used to show that. In the lottery winning transaction, the wallet involved in the bet was https://explorer.blockstamp.info/address/37qqxd5e5gXdDVv47t3JDyjteB7PL8 H9Q4 2 ​ 6

The link will show all transactions that went to and from that wallet. To find the transaction details, one needs to open the bet transaction by following the link under the winning transaction or by clicking on the link below TXID: 2 ​ 7

The transaction will show block height in its advanced properties (please refer to the t​ ransaction hash​ example). Having the hash and bet details, one needs to follow the calculations instruction to get the result. Similarly for a lost bet: https://explorer.blockstamp.info/address/37tePnymtSM33egBCpveSqcAsNXJ GPydRe​, the TXID link needs to be followed to obtain transaction data: 2 ​ 8

After that, the calculation instructions needs to be followed to verify the bet. 2.3.7. Mining and poles 2.3.7.1. Installation BlockStamp project’s code is available on our G ​ itHub project site​.To start using BlockStamp one should build the project and run a node with option -txindex to enable blockchain transaction queries. The node default configuration lets you connect to our working nodes. When connected to the existing node, the new node should start downloading blocks. After downloading process is completed, one can start working with BlockStamp. Default settings for BST are following: ● working directory: ~/.bst ● config file: bst.conf ● RPC port: 8445 ● peer-to-peer network port: 8446 ● executable names: bst* 2.3.7.2. Mining constraints Coinbase transaction in each of the blocks contains 50 BST, that are unspendable for the following 1000 blocks. A mining policy exists preventing blocks from being mined, if the rules are not followed. The rules are: ● The sum of input amounts for winning ​makebet​transactions included in a given block is not greater than 0.9 of a current block subsidy 2 ​ 9

(currently 50BST) and the sum of payoffs for for this block is not greater than the sum of inputs and the subsidy. ● The sum of payoffs for winning ​makebet​transactions included in a given block is not greater than maximum reward (1024*1024 BST, i.e. 1 048 576 BST). Miners can select the transactions they prefer to put into a block, based on the pools rules (e.g. fee, amount of a bet, potential reward). 2.3.8. The approach to casino’s profitability The project is maintained and developed by BlockStamp which is a non-profit organisation. Hence, the BlockStamp Games is not designed to be a profitable project. There are no hidden costs, fees, or edges as BlockStamp is not a side in the gaming. The project is open source and can be used by anyone who wishes so. The currency as well as the platform will be improved as much as possible by BlockStamp and its cooperators. 2.4. DNS 2.4.1. Description DNS service is build on the BlockStamp blockchain base. Details of domain names are stored in blocks. Transactions are used to: ● Create name ● Modify name details (change owner info, i.e. the wallet, modify expiration date which is 36000 blocks by default which is a year time) ● Search for a name (in order to verify if it is already taken or to check details of a specific name, like owner, expiry date, availability for sale) ● Show name history (this can be used to show historical data, like ownership, expiry, etc). It lists all entries related with the name provided as parameter. ● List all names that match a pattern (regex is used to define the pattern). No pattern means that 500 (or any other defined number) names will be listed starting from the defined block. ● List all unconfirmed operations related with DNS. This pan also be parameterized and a list of all operations related with a specific name can be obtained. 3 ​ 0

2.4.2. Usage I. bst-cli name_show​which looks up the current data for the given name and returns name, data, wallet information, update date, and expiry information if possible e.g. bst-cli name_show mydomain.com RETURN: { ​ ​"name": "mydomain.com", "name_encoding": "ascii", "value": "new-test-value", "value_encoding": "ascii", "txid": "d839cd97b2339fa3f204b5d38517480aa89d9b1cd5a6c6e4e6bf 09b611558967", "vout": 1, "address": "1FLF43YBB1JaKqLQFpoBkjsg8HTnWfFBwe", "height": 116181, "expires_in": 525596, "expired": false, "ismine": true } II. bst-cli name_history​which looks up the current and all past data for the given name and returns name, wallet information, update date, and expiry information for all the entries found for that specific name, e.g. bst-cli name_history mydomain.com III. bst-cli name_scan​which all names found in the database. It also accepts parameters (name to start from and number of blocks to show, which by default is 500) e.g. bst-cli name_scan mydomain.com { "name": "mydomain.com", "name_encoding": "ascii", "value": "for sale at 1BST", "value_encoding": "ascii", "txid": "d839cd97b2339fa3f204b5d38517480aa89d9b1cd5a6c6e4e6bf 09b611558967", "vout": 1, 3 ​ 1

"address": "1FLF43YBB1JaKqLQFpoBkjsg8HTnWfFBwe", "height": 116181, "expires_in": 525595, "expired": false, "ismine": true } IV. bst-cli name_filter​which shows all names found in the database that match the regular expression provided as parameter. It also accepts the following optional parameters: A. Maximal age (No of blocks to check back to) B. Height of the block to check from C. No of results to throw D. Stats - whether statistics is to be thrown instead of domain names Usage example: bst-cli name_filter [a-z]8[1-9]1 RETURN: ​ { "name": "mydomain1.com", "name_encoding": "ascii", "value": "not for sale", "value_encoding": "ascii", "txid": "d839cd97b2339fa3f204b5d38517480aa89d9b1cd5a6c6e4e6bf 09b611558967", "vout": 1, "address": "1FLF43YBB1JaKqLQFpoBkjsg8HTnWfFBwe", "height": 116182, "expires_in": 525595, "expired": false, "ismine": true } { "name": "mydomain2.com", "name_encoding": "ascii", "value": "not for sale", "value_encoding": "ascii", "txid": "4b5d38517480aa89d9b1cd5a6c6e4e6bf09b611558967d839cd9 7b2339fa3f20", "vout": 1, 3 ​ 2

"address": "1JaKqLQFpoFLF43YBB1Bkjsg8HTnWfFBwe", "height": 108181, "expires_in": 525595, "expired": false, "ismine": true } V. bst-cli name_pending​which shows all name related unconfirmed operations in the pool. It can be limited to a specific name only, if parametrised (name of the domain should be provided as parameter) Usage example: bst-cli name_pending RETURN: { "name": "mydomain.com", "name_encoding": "ascii", "value": "not for sale", "value_encoding": "ascii", "txid": "d7afa2230eec0a22fc9abfe0185fd507ce57a209d3eef6340641 c1e022a50cc0", "vout": 0, "address": "1PRqgLKvSwhqcoQgGt3CAD34M4ndMNEt2Z", "ismine": true, "op": "name_firstupdate" } VI. bst-cli name_checkdb ​which verifies the name db consistency. 2.4.3. Atomic transaction The idea of atomic transaction is to enable trustless transactions without the need of escrow. Atomic transaction is a transaction that ensures that either both elements of it happen simultaneously or none does. In case of DNS, this means that atomic transaction covers both aspects - domain name transfer and payment for the transfer, and ensures that they are treated as one logical operation. The below procedures are used to prepare an atomic transaction which will cover the whole sales/registration process. 3 ​ 3

I. bst-cli namerawtransaction ​which adds the name transaction to the new raw transaction. To create a new transaction, use Createrawtransaction ​procedure. It requires the following 3 parameters: ● The transaction hex string ● The vout of the desired name output ● Json object for name operation, where name_op can be any of the following: 1. Name_new (to create a new name entry in the database) 2. Name_firstupdate (to update a newly created name, and add ownership and expiry, or description/data) 3. Name_update (to update a name that already exists and is in use) Usage example: bst-cli namerawtransaction 8a592b73a8beb79cd0d73fc9bfb7c55de825ca981b5e35654cd22 28703694357582528d8ab01ffffffff03ca9a3b1976a9143c4b7d 4b93bc6194087bbbc422fd6cd1a40f820e88ac60ed3877161976a 914ab96be7f12bd38dd25b62be02b88ac40420f3f5310642f6d79 2d636f6f6c2d646f6d61696e117468616e6b732066726f6d20536 16c6c796d7576a914ad4a0929e9c7c95910534b93ec0727058a27 f2b988ac7102aabfac0ee6277ca45bccca1f98453101143993970 19ea12c8e243eb8839fed12ffffffff 1 {“op”:”name_new”, “name”:”mydomain.com”} RETURN: 25b62be02b88ac40420f3f5310642f6d792d636f6f6c2d646f6d6 1696e117468616eb79cd0d73fc9bfb7c55de825ca981b5e35654c d2228703694357582528d8ab01ffffe6b732066726f6d2053616c 6c796d7576a914ad77ca45bccca1f9845310114399397019ea12c 8e243eb8839fed12fff4a09298fffffa592b73a8bffff03ca9a3b 1976a9143c4b7d4b93bc6194087bbbc422fd6cd1a40f820e88ac6 0ed3877161976a914ab96be7f12bd38dde9c7c95910534b93ec07 27058a27f2b988ac7102aabfac0ee62 II. bst-cli Createrawtransaction ​which creates a transaction spending the given inputs (array containing txid and vout) and creating new outputs. Outputs can be an array of addresses or data. It returns hex-encoded raw transaction. Note that the transaction's inputs are not signed, and it is not stored in the wallet or transmitted to the network. In order to sign a raw transaction, please use S ​ ignrawtransactionwithkey​, in order to send the transaction to the network, use S​ endrawtransaction. Usage example: 3 ​ 4

bst-cli Createrawtransaction [{“txid”: “460ff04e500afd4c6164d70f0421b44e8d4979dfc11f33bf7f7c f3ad45333bb5”, “vout”:0}, {“34FYZErJ3CzdtQTjzxGyTPVrYBZAzeKKw4”:1.00, “3G8upiyMDTaA6YYiHUoUyikuBewoLGsuGt”:3.20}] RETURN: c9bfb7c55de825be7f12bd38dd25b62be02b88ac40420f3f53106 42f6d792d636f6f6c2d646f6d61696e117468616e6b732066726f 6d2053616c6c796d7576a914ad4a0929e9c7c95910534b93ec072 7058a27f2b988ac7102aabfac0ee6277ca45bccca1f9845310114 399397019ea12c8e243eb8839fed12ffffffff8a592b73a8beb79 cd0d73fca981b5e35654cd2228703694357582528d8ab01ffffff ff03ca9a3b1976a9143c4b7d4b93bc6194087bbbc422fd6cd1a40 f820e88ac60ed3877161976a914ab96 III. bst-cli Decoderawtransaction ​which decodes hex-encoded transaction, e.g. the product of ​Createrawtransaction​. It returns a JSON object representing the serialized, hex-encoded transaction. Usage example: bst-cli Decoderawtransaction c9bfb7c55de825be7f12bd38dd25b62be02b88ac40420f3f53106 42f6d792d636f6f6c2d646f6d61696e117468616e6b732066726f 6d2053616c6c796d7576a914ad4a0929e9c7c95910534b93ec072 7058a27f2b988ac7102aabfac0ee6277ca45bccca1f9845310114 399397019ea12c8e243eb8839fed12ffffffff8a592b73a8beb79 cd0d73fca981b5e35654cd2228703694357582528d8ab01ffffff ff03ca9a3b1976a9143c4b7d4b93bc6194087bbbc422fd6cd1a40 f820e88ac60ed3877161976a914ab96 RETURN: { "txid": "ad22e94a210df8ca340c208cdbc09d1e42775a03bb32b4db113e 76fb374b6495", "hash": "e5ec499bd7cec80a502252c25fca1df8de6876682b149e7ee4b6 da447c0833b7", "version": 2, "size": 388, "vsize": 225, "weight": 898, "locktime": 37932, "vin": [ { "txid": 3 ​ 5

"139c224c6ea460c7fb081c6e404a22e23d8afe666d742b001021 9f53ccbace18", "vout": 0, "scriptSig": { "asm": "0014b0b8ce35b26784d89431e15cecf025eed121d07c", "hex": "160014b0b8ce35b26784d89431e15cecf025eed121d07c" }, "txinwitness": [ "3045022100b9a53ac49bd2bef1c0fd07f34588d536aee166f5bf c047f75f17bc687699b5f4022064c6471d58a7705196bfd9272b0 4ca1b9ea05ff51cafffa85d252c308680fd7201", "03d14ee6f062e0cfcb7c5a9502a357ace8f7e2c07e96ec28d154 6633c673a8970e" ], "Value": 1 "sequence": 4294967293 }, { "txid": "3ff20f34d7790e4ba90f3914df511a86fc47ccbbb36ad154a612 0931f57a901a", "vout": 0, "scriptSig": { "asm": "0014b0b8ce35b26784d89431e15cecf025eed121d07c", "hex": "160014b0b8ce35b26784d89431e15cecf025eed121d07c" }, "txinwitness": [ "3045022100aeb015980ee237b8322af2e7f74b37c96b163fbffa 7099e8947a285765c596e302206cf805e54d5d5c3d89c3602e150 b2319d1749cbe982c99caf35bdda46babbd8701", "03d14ee6f062e0cfcb7c5a9502a357ace8f7e2c07e96ec28d154 6633c673a8970e" ], "sequence": 4294967293 } 3 ​ 6

], "vout": [ { "value": 1, "n": 0, "scriptPubKey": { "asm": "OP_HASH160 4244f06d6f6f29a69f259235bba944caca4edc11 OP_EQUAL", "hex": "a9144244f06d6f6f29a69f259235bba944caca4edc1187", "reqSigs": 1, "type": "scripthash", "addresses": [ "37jR7BWh6DhofUftXEBCMHD53FGwG4ckJK" ] } }, { "value" : 0.01000000, "n" : 2, "scriptPubKey" : { "nameOp" : { "op" : "name_update", "name" : "mydomain.com", "value" : "as agreed" }, "asm" : "NAME_OPERATION OP_DUP OP_HASH160 ad4a0929e9c7c95910534b93ec0727058a27f2b9 OP_EQUAL", "hex" : "5310642f6d792d636f6f6c2d646f6d61696e117468616e6b7320 66726f6d2053616c6c796d7576a914ad4a0929e9c7c95910534b9 3ec0727058a27f2b988ac", "reqSigs" : 1, "type" : "pubkeyhash", "addresses" : [ "0014b0b8ce35b26784d89431e15cecf025eed121d07c" ] } } ] } 3 ​ 7

IV. bst-cli Combinerawtransaction ​which combines multiple partially signed transactions into one transaction. The combined transaction may be another partially signed transaction or a fully signed transaction. It accepts an array of hex-encoded transactions (strings) and returns a hex-encoded s​ igned​ transaction. Usage example: bst-cli Combinerawtransaction e9c7c95910534b93ec0727058a27f2b988ac7102aabfac0ee6277 ca45bccca1f9845310114399397019ea12c8e243eb8839fed12ff ffffff8a592b73a8beb79cd0d73fc9bfb7c55de825ca981b5e356 54cd2228703694357582528d8ab01ffffffff03ca9a3b1976a914 3c4b7d4b93bc6194087bbbc422fd6cd1a40f820e88ac60ed38771 61976a914ab96be7f12bd38dd25b62be02b88ac40420f3f531064 2f6d792d636f6f6c2d646f6d61696e117468616e6b732066726f6 d2053616c6c796d7576a914ad4a0929, C9bfb7c55de825be7f12bd38dd25b62be02b88ac40420f3f53106 42f6d792d636f6f6c2d646f6d61696e117468616e6b732066726f 6d2053616c6c796d7576a914ad4a0929e9c7c95910534b93ec072 7058a27f2b988ac7102aabfac0ee6277ca45bccca1f9845310114 399397019ea12c8e243eb8839fed12ffffffff8a592b73a8beb79 cd0d73fca981b5e35654cd2228703694357582528d8ab01ffffff ff03ca9a3b1976a9143c4b7d4b93bc6194087bbbc422fd6cd1a40 f820e88ac60ed3877161976a914ab96 RETURN: 8a592b73a8beb79cd0d73fc9bfb7c55de825ca981b5e35654cd22 28703694357582528d8ab01ffffffff03ca9a3b1976a9143c4b7d 4b93bc6194087bbbc422fd6cd1a40f820e88ac60ed3877161976a 914ab96be7f12bd38dd25b62be02b88ac40420f3f5310642f6d79 2d636f6f6c2d646f6d61696e117468616e6b732066726f6d20536 16c6c796d7576a914ad4a0929e9c7c95910534b93ec0727058a27 f2b988ac7102aabfac0ee6277ca45bccca1f98453101143993970 19ea12c8e243eb8839fed12ffffffff V. bst-cli Sendrawtransaction ​which submits raw transaction (serialized, hex-encoded) to local node and network. It accepts hex of a signed raw transaction as input, and returns transaction hash. Usage example: bst-cli Sendrawtransaction 8a592b73a8beb79cd0d73fc9bfb7c55de825ca981b5e35654cd22 28703694357582528d8ab01ffffffff03ca9a3b1976a9143c4b7d 4b93bc6194087bbbc422fd6cd1a40f820e88ac60ed3877161976a 914ab96be7f12bd38dd25b62be02b88ac40420f3f5310642f6d79 2d636f6f6c2d646f6d61696e117468616e6b732066726f6d20536 16c6c796d7576a914ad4a0929e9c7c95910534b93ec0727058a27 3 ​ 8

f2b988ac7102aabfac0ee6277ca45bccca1f98453101143993970 19ea12c8e243eb8839fed12ffffffff RETURN: 460ff04e500afd4c6164d70f0421b44e8d4979dfc11f33bf7f7cf 3ad45333bb5 VI. bst-cli signrawtransactionwithkey ​which signs raw transaction (serialized, hex-encoded). The second argument is an array of base58-encoded private keys that will be the only keys used to sign the transaction. The third optional argument (may be null) is an array of previous transaction outputs that this transaction depends on but may not yet be in the blockchain. It returns signed transaction hex, completion status (true/false) with errors in case of any. bst-cli signrawtransactionwithkey 8a592b73a8beb79cd0d73fc9bfb7c55de825ca981b5e35654cd22 28703694357582528d8ab01ffffffff03ca9a3b1976a9143c4b7d 4b93bc6194087bbbc422fd6cd1a40f820e88ac60ed3877161976a 914ab96be7f12bd38dd25b62be02b88ac40420f3f5310642f6d79 2d636f6f6c2d646f6d61696e117468616e6b732066726f6d20536 16c6c796d7576a914ad4a0929e9c7c95910534b93ec0727058a27 f2b988ac7102aabfac0ee6277ca45bccca1f98453101143993970 19ea12c8e243eb8839fed12ffffffff [{5Kb8kLf9zgWQnogidDA76MzPL6TsZZY36hWXMssSzNydYXYB9KF }] RETURN: D6cd1a40f820e88ac60ed3877161976a914ab96be7f12bd38dd25 b62be02b88ac40420f3f53128d8ab01ffff0642f6d792d636f6f6 c2d646f6d61696e117468616e6b732066726f6d2053616c6c796d 7576a914ad4a0929e9c7c95910534b93ec0727058a27f2b988ac7 102aabfac0ee6277ca45bccca1f9845310114399397019ea12c8e 243eb8839fed12ffffffff8a592b73a8beb79cd0d73fc9bfb7c55 de825ca981b5e35654cd22287036943575825ffff03ca9a3b1976 a9143c4b7d4b93bc6194087bbbc422f, true 2.4.4. Workflow example In a theoretical scenario, John owns a domain mydomain.com which Mary is interested in. Mary can use ​bst-cli name_show mydomain.com ​to find details about who owns the domain and how the domain can be obtained. The command returns the following info: mydomain.com, “current price 1BST paid to 34FYZErJ3CzdtQTjzxGyTPVrYBZAzeKKw4” 3G8upiyMDTaA6YYiHUoUyikuBewoLGsuGt 3 ​ 9

Which means that mydomain.com is for sale at 1BST price. The money needs to be transferred to the wallet address provided in the data info. The wallet containing the domain name is the bottom one. If Mary wants the domain for 1BST, she needs to prepare an atomic transaction that will contain both the transfer and the payment. First, she needs to prepare the payment information, i.e. the transaction id of a transaction which unspent output can cover the transfer, and the vout of the transaction output to be used. For example, if Mary owns 4 BST from an unspent transaction, she needs to send 1BST to John and the rest to a wallet she creates for the purpose. Given that the vout to be used is the first on the list, its number is 0. Based on that info, she can create a new raw transaction. See the example below: bst-cli Createrawtransaction [{“txid”: “460ff04e500afd4c6164d70f0421b44e8d4979dfc11f33bf7f7c f3ad45333bb5”, “vout”:0}, {“34FYZErJ3CzdtQTjzxGyTPVrYBZAzeKKw4”:1.00, “3G8upiyMDTaA6YYiHUoUyikuBewoLGsuGt”:3.20}] Next, Mary needs to create name_operation details and add them to the raw transaction by using namerawtransaction. For example: bst-cli namerawtransaction 8a592b73a8beb79cd0d73fc9bfb7c55de825ca981b5e35654cd22 28703694357582528d8ab01ffffffff03ca9a3b1976a9143c4b7d 4b93bc6194087bbbc422fd6cd1a40f820e88ac60ed3877161976a 914ab96be7f12bd38dd25b62be02b88ac40420f3f5310642f6d79 2d636f6f6c2d646f6d61696e117468616e6b732066726f6d20536 16c6c796d7576a914ad4a0929e9c7c95910534b93ec0727058a27 f2b988ac7102aabfac0ee6277ca45bccca1f98453101143993970 19ea12c8e243eb8839fed12ffffffff 1 {“op”:”name_update”, “name”:”mydomain.com” “value”:”not for sale”} The transaction needs to be signed before it is sent for verification to John. For that purpose, Mary can use ​bst-cli signrawtransactionwithkey ​using the transaction hex obtained as a result of​ namerawtransaction. ​Mary can either use her private key stored locally, or an existing key that she stored in the blockchain. 4 ​ 0

The hex of the partially signed transaction can be sent to John, who can decode the transaction in order to verify it. If John is happy with the transaction, he can sign it with a key and send it to the blockchain using b​ st-cli Sendrawtransaction​ . In return he will get a hash of the transaction. When the transaction is confirmed, the operations take place and Mary becomes the new owner of mydomain.com. 2.5. Desktop application & Wallet The desktop application serves as a desktop interface to the blockchain. The application offers the below described functionalities. In addition to that, it also allows to encrypt the wallet, sign or verify message. The latter can be used in the above scenario, for DNS raw transaction signing. 2.5.1. Value transfer Desktop application can be used to send and request/receive value transfers in BST. 4 ​ 1

The transfer tab allows user to define the fee and choosing confirmation target time by selecting from the recommended fees or defining one's own. 2.5.2. Gaming The application provides betting interface for lottery and roulette. It allows to define numbers and probability (modulo) for lottery or select bet type for roulette. As in the value transfer, Bets tab also allows users to define the fee they want to pay, or even select 0.00 BST fee. 2.5.3. Data Data tab provides three basic functionalities - Store, Retrieve, and Check. 4 ​ 2

Store option allows to store a message, a file, or a file signature in the blockchain. Again, it allows to define the fee one wants to pay. Retrieve option returns content of a transaction in String or Hex. It also allows to store the content in a file. Check option allows to verify content of a transaction and compare it with data provided by user (in a file or message). 4 ​ 3

3. Appendix 1 - bet types, syntax, and numbers 1. straight: straight_1, straight_2, ...,straight_36. 2. split: split_1={1, 4}, split_2={4, 7}, split_3={7, 10}, split_4={10, 13}, split_5={13, 16}, split_6={16, 19}, split_7={19, 22}, split_8={22, 25}, split_9={25, 28}, split_10={28, 31}, split_11={31, 34}, split_12={2, 5}, split_13={5, 8}, split_14={8, 11}, split_15={11, 14}, split_16={14, 17}, split_17={17, 20}, split_18={20, 23}, split_19={23, 26}, split_20={26, 29}, split_21={29, 32}, split_22={32, 35}, split_23={3, 6}, split_24={6, 9}, 4 ​ 4

split_25={9, 12}, split_26={12, 15}, split_27={15, 18}, split_28={18, 21}, split_29={21, 24}, split_30={24, 27}, split_31={27, 30}, split_32={30, 33}, split_33={33, 36}, split_34={1, 2}, split_35={2, 3}, split_36={4, 5}, split_37={5, 6}, split_38={7, 8}, split_39={8, 9}, split_40={10, 11}, split_41={11, 12}, split_42={13, 14}, split_43={14, 15}, split_44={16, 17}, split_45={17, 18}, split_46={19, 20}, split_47={20, 21}, split_48={22, 23}, split_49={23, 24}, split_50={25, 26}, split_51={26, 27}, split_52={28, 29}, split_53={29, 30}, split_54={31, 32}, split_55={32, 33}, split_56={34, 35}, split_57={35, 36} 3. street: street_1={1, 2, 3}, street_2={4, 5, 6}, street_3={7, 8, 9}, street_4={10, 11, 12}, street_5={13, 14, 15}, street_6={16, 17, 18}, street_7={19, 20, 21}, street_8={22, 23, 24}, street_9={25, 26, 27}, 4 ​ 5

street_10={28, 29, 30}, street_11={31, 32, 33}, street_12={34, 35, 36} 4. corner: corner_1={1, 2, 4, 5}, corner_2={4, 5, 7, 8}, corner_3={7, 8, 10, 11}, corner_4={10, 11, 13, 14}, corner_5={13, 14, 16, 17}, corner_6={16, 17, 19, 20}, corner_7={19, 20, 22, 23}, corner_8={22, 23, 25, 26}, corner_9={25, 26, 28, 29}, corner_10={28, 29, 31, 32}, corner_11={31, 32, 34, 35}, corner_12={2, 3, 5, 6}, corner_13={5, 6, 8, 9}, corner_14={8, 9, 11, 12}, corner_15={11, 12, 14, 15}, corner_16={14, 15, 17, 18}, corner_17={17, 18, 20, 21}, corner_18={20, 21, 23, 24}, corner_19={23, 24, 26, 27}, corner_20={26, 27, 29, 30}, corner_21={29, 30, 32, 33}, corner_22={32, 33, 35, 36} 5. line: line_1={1, 2, 3, 4, 5, 6}, line_2={4, 5, 6, 7, 8, 9}, line_3={7, 8, 9, 10, 11, 12}, line_4={10, 11, 12, 13, 14, 15}, line_5={13, 14, 15, 16, 17, 18}, line_6={16, 17, 18, 19, 20, 21}, line_7={19, 20, 21, 22, 23, 24}, line_8={22, 23, 24, 25, 26, 27}, line_9={25, 26, 27, 28, 29, 30}, line_10={28, 29, 30, 31, 32, 33}, line_11={31, 32, 33, 34, 35, 36} 6. column: column_1={1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31, 34}, column_2={2, 5, 8, 11, 14, 17, 20, 23, 26, 29, 32, 35}, column_3={3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36} 7. dozen: 4 ​ 6

dozen_1={1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}, dozen_2={13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24}, dozen_3={25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36} 8. low: low={1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18} 9. high: high={19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36} 10. even: even={2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36} 11. odd: odd={1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35} 12. black: black={2, 4, 6, 8, 10, 11, 13, 15, 17, 20, 22, 24, 26, 28, 29, 31, 33, 35} 13. red: red={1, 3, 5, 7, 9, 12, 14, 16, 18, 19, 21, 23, 25, 27, 30, 32, 34, 36} 4 ​ 7