• Contentos is a blockchain-based decentralized digital content platform. The project has raised ~$31MM via private token sales, and is founded by Mick Tsai.

• Contentos utilizes self-adaptive Byzantine Fault Tolerance (saBFT) mechanism to achieve fast consensus.

• Contentos is attempting to build a decentralized digital content community, which would allow content to be freely produced, distributed, rewarded, and traded, while protecting author rights.

• COS is the native asset in the Contentos blockchain: it is used for voting, paying gas fee for smart-contract execution, and simple transaction fee.

1. What is Contentos (COS)?

Contentos is building a blockchain-based decentralized content ecosystem. The vision of Contentos is to build a "decentralized digital content community that allows content to be freely produced, distributed, rewarded, and traded, while protecting author rights". Contentos strives to incentivize content creation and global diversity and return the rights and value of content to users. Contentos aims to be a public content protocol that not only carries content and advertising value but is also a memory chain recording each user's contributions.

Contentos features:

• Peer-to-peer revenue distribution: Contentos provides open and transparent payment channels among content creators, advertisers, and audiences. The tokens as subscription fee, gifting, or sponsorship can be tracked on blockchain transactions. Contentos will also provide a smart contract template which automates content monetization.

• Decentralized traffic distribution: the Contentos blockchain is designed to facilitate content distribution free from platform control. The built-in ecological reward motivates content creators to improve their creations, audiences to interact with content they truly appreciate, and the community and dApp developers to design the best strategy to deliver favorable content to corresponding audience.

• Trackable copyright transaction: verification, trade, and storage of non-physical property rights through Contentos blockchain will enable quick and comprehensive access to copyright information. Trade flows and derivative works will be recorded permanently on the blockchain. Content creators will register their copyright and provide original content statements, authenticated and traced with time stamps.

• Immutable credit system: in the Contentos ecosystem, user interactions are tracked on the blockchain and cannot be tampered with. Users can improve their credit scores only through demonstrating positive and trustworthy behaviors, thereby becoming eligible for ecological rewards and increasing their credibility. In this way, the users collectively build a reliable, self-sustaining review system.

Some of its key highlights include:

• Content industry-optimized public chain: to better support the massive interactions of the content community, Contentos implemented saBFT, or self-adaptive Byzantine Fault Tolerance consensus mechanism, which enables low-fee transactions and low block confirmation time.

• Data-based ecological reward model: the built-in ecological reward model encourages positive contributions in the ecosystem. Contentos is currently building its reward model based on the actual data collected from testnet integrations in order to avoid issues such as rewards being dominated by senior users with large amounts of tokens.

• Open platform: Contentos has been actively reaching out to dApps across different blockchains. Partnerships with mature dApps like PhotoGrid and LiveMe made it easy for Contentos to introduce non-crypto users to the blockchain world and start using the partnered dApps. With account and token integration, the open platform initiated by Contentos is aimmed at benefiting to benefit the whole blockchain industry.

2. Products and technological architecture

2.1 Products and metrics

Since Contentos launched its testnet in March 2019, 4 dApps have been integrated to the Contentos Platform: PhotoGrid, COS2048, WalkCoin, and .

Current statistics of all dApps running on Contentos can be found here.

PhotoGrid

PhotoGrid is a popular photo editing App with a community similar to that of Instagram. PhotoGrid is powered by Contentos testnet and actual COS tokens. PhotoGrid is available on both iOS and Android.

COS2048

COS2048 is an Android game App derived from the original 2048 game. Users are able to earn COS through single-player games and use them as bet in double-player games.

WalkCoin

WalkCoin is an Android App that keeps track of users' walking record. WalkCoin issues Energy Coins (ENC) on Contentos testnet as an incentive to motivate users to achieve their exercise goals. Users can earn Energy Coins by completing walking tasks.

COS.TV

COS.TV shares project information and serves as a blockchain explorer. The platform is also a wallet for COS holders. Within the wallet, users are able to bind COS-enabled App accounts and withdraw COS to their BNB wallets. The website also displays selective video content and live streams from LiveMe. The interactions between users and content such as posts, likes and comments are recorded on the Contentos testnet.

2.2 Blockchain and network data

Identity Authentication system

Every Contentos user has 2 IDs, one is her elliptic curve public key and the other is her unique account name. Account names are essentially readable aliases of public keys. All user properties such as IDs, balances and credits are grouped and maintained as on-chain account records that are freely accessible to the public.

Transactions and blocks must be signed by their originators. Contentos only accept transactions which have passed signature verification. The elliptic curve digital signature algorithm ensures everything on-chain is both unfraudable and undeniable.

Content Copyright Management contract

Contentos Copyright Management is a system smart contract. Block producers can use the contract to elect a copyright moderator, who then has access by calling the contract to mark any content as genuine or pirated. Pirated content will be ignored by the reward distribution system and brings no benefits to their creators.

In practice, a copyright moderator is an account owned by a professional entity who has a strong ability on copyright authentication and are trusted by majority of block producers.

User Credibility contract

The Credibility Management contract is very similar to that of Copyright Management. Once a moderator is elected by block producers, she can then call the contract to set anyone's credit.

WASM smart contracts

Contentos supports smart contracts in WebAssembly bytecodes. Any programming language can be used for contract development as long as its compiler supports WebAssembly. For maximum efficiency and convenience, the Contentos team recommends C++, and provides both a C++ SDK and an online IDE.

Developers can implement arbitrary logic in a contract since the programming language is Turing complete. Under the help of SDK, a contract also has access to rich on-chain data and permanent storage.

Storage mechanism

Currently, only links of contents are stored on chain. Contents are stored by each dApp mostly in centralized cloud storages like Amazon S3, since decentralized storage systems like IPFS and FileCoin are still in their infancy.

Technical architecture layers

The following chart is a visualization of Contentos' technical architecture layers.

Protocol layer

The protocol layer implements fundamental infrastructures such as gossip network, general-purpose consensus protocol, distributed ledger, cryptographic math and smart contract virtual machine. It defines the technical possibility of Contentos.

API layer

API layer defines the basic business model of Contentos. As of writing, Contentos has implemented sub-systems of account management, credibility management, block producer election, asset trading, copyright management, content publishing, tipping and reward distribution. More rules could be added in the future.

Application layer

Contentos provides various kinds of contract templates and online contract generator with one-click deployment feature. The team notes that the Application Layer is still in its early stage of developmemt.

A BFT + DPoS proprietary consensus: saBFT consensus

Below shows a high-level description of the saBFT Consensus.

Contentos deploys a BFT+DPoS-based consensus protocol called saBFT ("self-adaptive Byzantine Fault Tolerance"). In saBFT, the BFT voting process is separated from the block-producing process. Unlike other BFT family protocols, the Contentos network runs BFT and block-producing asynchronously so that blocks can be committed in batches. This is aimed to overcome network jitters and achieve finality more quickly without compromising safety and liveness.

Block producers are elected in a standard DPoS way, i.e., users vote for candidates and the more tokens staked, the more voting power. Producers create new blocks in turns and are replaced by new producers periodically.

A Tendermint-like 3-step voting BFT process runs in parallel to mark the finality of blocks. Block producers are also BFT validators, who always propose their local head block and vote for blocks on their local chain. When a block is proposed and agreed by 2/3+ majority in 2 rounds of voting, it reaches finality. Block finality also helps a validator switch forks when she finds her head block and the finalized block branches off.

3. Economics and supply

3.1 Token supply distribution

The token supply distribution is as follows:

• Strategic Sale tokens comprise 9.5% of the total token supply. It was conducted from 1 March 2018 to 30 March 2018 for 950,000,000 COS at a rate of 53,334 COS = 1 ETH and raised a total of 17,812 ETH (~$14.25MM, with an average ETH price of $800.02) at $0.015 per token, selling 9.5% of the total token supply.

• Seed Sale tokens comprise 11.32% of the total token supply. It was conducted from 1 April 2018 to 30 June 2018 for 1,131,726,517 COS at a rate of 40,000 COS = 1 ETH and raised a total of 28,293 ETH (~$16.98MM, with an average ETH price of $600.00) at $0.015 per token, selling 11.32% of the total token supply.

• Team tokens comprise 15% of the total token supply.

• Advisor tokens comprise 0.5% of the total token supply.

• Foundation Reserved tokens comprise 18.68% of the total token supply.

• App Jumpstart Reward tokens comprise 5% of the total token supply.

• Ecosystem Reward tokens comprise 35% of the total token supply.

• Community Development tokens comprise 3.5% of the total token supply.

• Token Treasury tokens comprise 1.5% of the total token supply.

COS token distribution (%)

As of July 2019, the Contentos team has used 6.22 million USD, or 20% of its funds according to the allocations below:

• 13% Content Development.

• 22% Marketing.

• 19% Operations.

• 18% Research & Development.

• 20% Business Development.

• 8% Professional Services & Administrative.

Contentos holds 96% of its crypto funds in several cold wallets with multi-sig protection. Only multiple C-level management's joint authorization can move funds stored in the cold wallets. 4% of crypto funds are stored in multiple hot wallets and require different levels of authorization before making any payment.

3.2 COS token release schedule

The following chart represents the number and breakdown of all COS tokens that are to be released into circulation on a monthly basis. Note that the Ecosystem Reward will be fully distributed over a 12-year period.

COS token release schedule

3.3 COS token overview and use-cases

COS is the native utility token in the Contentos ecosystem. Its usage includes the following:

• Voting and election: by staking COS, anyone can be eligible to participate in a block producer election.

• Gas fee: on the Contentos platform, all users receive a certain amount of "energy" (gas) for smart-contract executions. However, once the default "energy" runs out, users need to stake COS in order to acquire "energy".

• Transaction: content-related micro transactions such as content subscription or donation can be settled in COS. Any commercial transaction, such as payment for advertisement between the advertiser and the influencer can also be settled with COS.

4. Roadmap, updates, and business development

4.1 Original roadmap and achievements

4.2 Late milestone

PhotoGrid was planned to be integrated onto the Contentos platform by Q3 2018. However, the PhotoGrid integration was delayed to Q4 2018 due to changes in PhotoGrid's development plan.

4.3 Updated roadmap

Q3 2019

• Mainnet launch.

• Launch Global Content Creator Education Program.

Q4 2019

• Launch Content Diversification Program.

• Launch Contentos v1.1 Enhancement Plan.

4.4 Commercial partnerships and business development progress

• TomoChain: TomoChain is a public blockchain platform based in Southeast Asia. TomoChain is partnering with Contentos to explore decentralized advertising, starting with TomoChain's dApp promotions.

• KardiaChain: KardiaChain is an interoperable blockchain platform for decentralized applications. Contentos is working with KardiaChain to explore interoperability via the transfer of assets and data between blockchains and applications for consumers and businesses.

• Nexty: Nexty is a Vietnam based blockchain platform for ecommerce and retail payment. Contentos has partnered with Nexty to explore the space of e-payments in Vietnam.

• Bitsclub Vision Program: Bitsclub Vision Program aims to create seamless connection between the traditional industries and the blockchain space. Contentos is joining the alliance to further expand its blockchain ecosystem and investigate potential business opportunities as a collaborative unit.

• MIXMARVEL: MIXMARVEL is a blockchain based game issuance platform. HyperSnakes, a game originating from MIXMARVEL, is currently being advertised within Contentos' content ecosystem.

• Harmony: Harmony is a blockchain platform which aim to achieve scalability through sharding. Harmony's Puzzle game is currently being advertised within Contentos' content ecosystem.

• Blockchain Cuties: Blockchain Cuties is a crypto collectible game. COS token has been integrated to be a part of the Blockchain Cuties in-game market and Contentos assisted them in entering the Vietnam market.

• Somesing: Somesing is a blockchain based social music Karaoke App built on ICON. Somesing has partnered with Contentos to expand its user base.

• Unlimited Tower: Unlimited Tower is an on-chain RPG dApp game built on EOS. Unlimited Tower has partnered with Contentos to increase its exposure amongst Contentos users.

• ITAM GAMES: ITAM GAMES is a company seeking to innovate the gaming ecosystem by putting achievements, leaderboards, and in-game assets on blockchain. Contentos will be collaborating with ITAM GAMES on user acquisition.

5. Project team

6. Contentos' activity and community overview

6.1 Social and community data

Strategy overview

Contentos strives to build a global decentralized content ecosystem, with an initial concentration in the Asia-Pacific region (China, Taiwan, Vietnam, Japan, South Korea).

Contentos primarily collaborates with:

• Tier 2 content creators (accounts with 500K to 1MM subscribers on Youtube) in the initial stage and connect users from Contentos partner dApp to the world of blockchain.

• Tier 1 content creators (accounts with more than 1MM subscribers on Youtube) to raise brand awareness and bring more users to the Contentos ecosystem by organizing community activities.

Online community building strategies

• Creator Incentive Program which incentivizes passionate content creators to start creating content and hosting it on COS.TV.

• Daily quizzes via social media channels (Line, Twitter, WeChat etc) to interact and engage in the wider community.

Offline community building strategies

Contentos has been active in many blockchain and crypto related events. Upcoming events include ChinaJoy in Shanghai, and Taipei International Comics & Animation Festival in Taiwan.

Technical community building strategies

• Future hackathons and technical sessions to engage with developers.

• Technical AMAs to facilitate the engagement of Contentos developer scene.

Ecological operation reward

3.5 billion COS tokens (i.e., 35% of total token supply) will be used as ecosystem rewards, which will be released over 12 years. The annual release amount will increase based on the total number of Contentos users. In the first year, 0.448% of all tokens will be released, and the amount will increase linearly every year until the release of 5.432% in the 12th year.

Contentos hopes that the gradual release of tokens with reference to user growth will help to stabilize the price of tokens and grant appropriate rewards to early participants.

75% of the regular reward tokens will be used to motivate users to create content and participate in ecosystem operations. Another 10% will be used to reward dApp developers for creating a better user experience and thus attracting more users to join the Contentos ecosystem through the dApp. Finally, 15% of the regular reward tokens will be the incentive for block producers.

DApp kick-start reward

To attract more users to participate in the early stages of Contentos, 500 million tokens (i.e., 5% of the total supply) will be offered to the dApp developers recognized by the Foundation to design relevant functions and reward methods to encourage users to join the Contentos ecosystem.

These kick-start reward tokens are released yearly over 5 years.

Community and social channels

Telegram (English)
Telegram (Vietnamese)
Twitter (English)
Facebook (Chinese)
Medium (English)

7. Appendix

Advisors

• Shao Bo

• Hitters Xu

• Charles Fan

• Ricky Ray Butler

Media mentions

• Business Wire: Contentos Announces Investment From Binance Labs, Fund Created By One of the Largest Cryptocurrency Exchanges in the World

• CCN: COS Takes Global Tour to Tokyo to Create Value for Millions of Content Creators Worldwide

• Benzinga: Contentos Announces Investment and Partnership with NEO Foundation

• Block Publisher: How Contentos Will Tackle The Blockchain Scalability Problem? According to Co-founder

• CryptoNewsZ: Binance Labs Awards Grants To Three Blockchain Start-ups, Each To Get $15,000

• CoinPost: ビットコインは 70 万円台まで高騰、異常な強さにある「5 つの理由」と今後の展望｜仮想通貨市況

• Yahoo Finance: The highly anticipated platform token of MixMarvel goes for co-initial-listing on Korea's leading exchanges

• Yahoo Finance: Contentos Joining Binance Chain To Explore the Content Blockchain Ecology

• Business Wire: Contentos Announces Listing on Binance DEX

• CryptoNewsZ: Binance Charity Partners With 46 Companies To Unveil New Stablecoin "Pink Care Token"