Dongsam Byun [변동삼]

Blockchain Engineer, Security Auditor, Bug Hunter

Cosmos-SDK / CometBFT / Ethereum / Go

dongsamb@gmail.com | dongsam

Experience

2022- Stealth mode

-Achieved 1st place ranking in Cosmos official bug bounty program on HackerOne

-ASA-2024-001: Validation of VoteExtensionsEnableHeight can cause chain halt

-ASA-2024-003: Missing BlockedAddressed Validation in Vesting Module

2022 Crescent Network , Blockchain Engineer

-Maintaining Crescent Network Core

-Developing liquidstaking, mint, marketmaker modules

2021 Tendermint

-Tendermint has acquired B-Harvest

-Developing budget, farming modules -Developing Gravity-DEX, Liquidity Module on Cosmos Hub

2018-2022 B-Harvest, CTO

-Developing tendermint Liquidity Module of the Cosmos-SDK, which serves AMM(Automated Market Makers) on Cosmos Hub ( Gravity-DEX )

-Contributing Cosmos-SDK, Tendermint open-source and Customizing for analysis, validation

-Development and Consulting, Auditing of Blockchains Based on Cosmos-SDK and Tendermint (Kava, Terra, etc.)

-Building, managing, and optimizing for Cosmos validator(DPoS) node system, Reliability Engineering

-Cosmos, Terra, IRIS, Kava, Chainlink, Secret Network, Band Protocol, etc Validator ( moniker: B-Harvest )

-Ranked Top Tier in Cosmos Game of Stakes (moniker: bharvest)

-Reporting critical security vulnerability ( Gaia, Cosmos-SDK, Cosmos-Hub )

-Designing Tokenized Fund using Smart Contracts

2018 The Language Network(Atlas Labs), Lead Blockchain Engineer

-Developed Smart Contract, Dapp for publishing ERC20 Token and ICO

-Implemented Blockchain Backend Server using Geth and web3.py

-Built Ethereum Blockchain Network as a sidechain and Ledger

2017 Self-employed, Freelancer Blockchain Engineer, Advisor, Lecturer, Author

-Advice for ICO and Blockchain Projects

-Blockchain Advisory Board Member, IIB Council

-Lecture on Ethereum and Solidity Programming Course, Fast campus

-Auditing Smart Contracts (Solidity)


2016-17 WantedLab, Machine Learning, Software Engineer (Matching Cell)

원티드 (wanted.co.kr) Data Analysis, Machine Learning, Backend, REST API Development

-Implemented morphological analysis and extract keyword of Resume, Job Description text ( NLP, TF-IDF, Word2vec )

-Developed matching model and scoring system for between user and job ( Collaborative Filtering )

-Optimized feature for matching model using DNN, Tensorflow

-Developed auto Crawling system for company news with noise filtering

2016 Cheoum, Lead Developer

CUfund Backend, Full Stack of P2P, P2B Crowd Funding Platform

-Developed whole web service of P2P Loan Platform

-Implemented Credit rating inquiry, identity verification, virtual account integration system

-Built infrastructure and DevOps using AWS

2015-16 DAYLI Financial Group(Nomad Connection), Researcher(DataLabs)

-Developed Log Collecting and analysis system for web page

-Did research and analyze news text for stock investment ( Word2Vec, Doc2Vec )

2014-15 Self-employed, Freelancer

Web, Data Crawler Development

Automation

-Browser Automation for SEO [ Python, Selenium ]

-Business Automation for law firm [ Python, Flask ]

-Instagram Image Upload Automation [ Python ]

-Facebook Page Posting Automation [ Python, GraphAPI ]

Education

2015-18 Korea University, M.S. in Computer Science and Engineering

2011-15 Dongguk University, B.S. in Computer Science and Engineering

Pizza Sales Prediction by Using Big Data Analysis / KIPS 2014 Fall Conference VOL 21 NO. 02 PP. 0890 ~ 0893 (2014. 11)

AI Lab (RA, TA)

Contributions [github]

Projects

2020 Liquidity: Tendermint AMM Liquidity Module of Cosmos-SDK [github]

2019 Four-Pillars-Project: better validator operation of Tendermint/Cosmos-SDK [github]

2017 Coin-Trends: CryptoCurrency Analysis Using Text Mining and Machine Learning [github]

Quantitative Analysis, Text Mining, Open-Source Analysis, Machine Learning Approach

Sentiment Analysis about Chatting data using doc2vec [github]

2015 Logdig: Web/App Big Log Analysis Framework [github]

A framework that allows users to generate, collect, analyze, and visualize click, move, and exit logs generated by Web / App services

Flask RESTful Server, Spark, Zepplien Dashboard

2014 Sales forecast system through big data analysis [youtube]

Forecasts future sales volume by analyzing 10-year sales data on POS, online, and phone order share in the foodservice industry and external variables such as weather, news, weblog, and marketing information

Data ETL using Python, Pandas, and Machine Learning with Weka, Jython

2013 System Trading by New Opinion Mining [youtube]

Signal generation through real-time news crawling and positive, negative opinion mining

Project Manager, Python, XingAPI(Etrade)

2012 Secure payment system based on QRcode scan [youtube]

Make payment by QRcode scan with sales information, By encrypting the user authentication and credit information required for payment and storing it on a personal smartphone rather than on a server

Project Manager, Payment, Verification Server QRcode Manage Server, POS, Web/App Client

Activities

2024 Achieved 1st place ranking in Cosmos official bug bounty program on HackerOne.

2021 Reporting critical security vulnerability ( Gaia, Cosmos-SDK, Cosmos-Hub )

2020 Cosmos Community Contributor Grants

2019 Cosmos Berlin Hackatom 2019, Honorable Mention, dDex: decentralized Delegation Exchange

2018 Technical Mentoring, Judging for Blockathon ( Blockchain Hackathon ), Fastcampus

2015 Korea University CCS Lab(Computer & Communication Security Laboratory) Full-Time

2014-16 public-private joint investigation team for cybersecurity, [ Korea Ministry of Science and ICT ]

2014 Dongguk University AI Lab TA, RA

2013-14Software Maestro 4th Step 2, Top 50 [ Korea Ministry of Science and ICT, NIPA ]

2012-13BEST OF THE BEST 1st Step3, Top 20 finalists, Cyber Security Elite Training program [ Korea Ministry of Science and ICT, Kitri ]

2011-12 Microsoft Student Partner 5th [ Microsoft Korea ]

Presentations

2019 Database, Statistics, and Data Mining in dPoS Blockchain, Cosmos Seoul Hackatom 2019

2018 Trends and View about Blockchain Development, Web World Contents Service Conference 2018

2017 Consensus Algorithm of Ethereum and Mining Flow, Korea Ethereum Research Group, Google Campus Seoul

2017 Ethereum A to Z, BlockChain Business Research Group

2017 Machine Learning Engineer Meetup, WANTED x wework

2015 Whitebox Testing, 2015 monsterz seminar, Hanyang Univ.

2014 Sales Prediction System by Using Big Data Analysis, Hanium expo 2014, COEX [youtube]

2014 Drone-based tour and control systems with Cisco CMX technology, CISCO IoE Codefest, Song-do [youtube]

2013 Secure payment system based on QR code scan, COEX [youtube]

Training

2014 Training and exploration at Silicon Valley, Google, MS, Stanford, HP, etc.

2013-14 Software Maestro summer, winter education, and training

2012 Cyber Security Elite Training program BoB education and training

Prizes

2014 Computer Engineering General Design Project, Grand Prize [Dongguk Univ.]

2013 Software engineering project, Grand Prize [Dongguk Univ.]

2013 2nd TOPCIT competition, Special prize [Korea Ministry of Science and ICT, NIPA]

2013 APT attack simulation competition for enterprise security experts, 3rd place [Symantec]

2011 Technical report writing and presentation contest, Grand Prize[1st] [Dongguk Univ.]

2010 Open source software introduction essay contest, 2nd place [redhat Korea]

Publications, Patents

2021 Proposal for Cosmos based Automated Market Maker, Liquidity Module

2014 Pizza Sales Prediction by Using Big Data Analysis / KIPS 2014 Fall Conference VOL 21 NO. 02 PP. 0890 ~ 0893 (2014. 11)

2014 AUTOMATIC SALES FORECASTING SYSTEM BASED ON DATA CRAWLING AND MANAGER’S INPUT (Publication, 1020140157122)

2013 SYSTEM AND A METHOD FOR TRADING STOCKS AUTOMATICALLY BASED ON OPINION MINING (Publication, 1020130142019)

2013 THE SECURITY ONLINE PAYMENT SYSTEM AND THOSE METHODS BASED ON TWO DIMENSIONS CODE SCANNING WITH A DEVICE CONTAINING ENCRYPTED PAYMENT AUTHENTICATION INFORMATION (Publication, 1020130001343)

2012 SECURITY PAYMENT SYSTEM BASED ON A CODE SCAN THROUGH A TERMINAL STORING ENCODED AUTHENTICATION INFORMATION AND A METHOD THEREOF FOR SAFELY PERFORMING AUTHENTICATION AND PAYMENT (Publication, 1020120062929)

Certifications

2014 Engineer Information Processing (Human Resources Development Service Of Korea)

2010 LPIC (LPI)

2010 CCNA (CISCO)

2009 Certificate of Hacking Security Expert (National Association of Hacking & Security)