How can the city government track the entire flow of public finance — from budget approval to final contractor — using digital tools like blockchain?
The Problem
Problem Background
Financial transparency in public works is critical worldwide. Colombia, in particular, continues to face high corruption indices despite various efforts to enhance public financial transparency. According to the Corruption Perception Index(CPI) released by Transparency International, Colombia scored 39 out of 100, with an average score of 35.53 between 1995 and 20241. The Control of Corruption, which measures perceptions of the extent to which public power is exercised for private gain, also placed Colombia in the 44.81 percentile among all countries covered by the aggregate indicator2. This indicates that public financial transparency remains an unresolved challenge in Colombia.
The report “Radiography of corruption in Colombia 2021-2022” includes the sectors and types of corruption in Colombia, and reveals that approximately 62.7% of reported corruption cases are administrative corruption, making it the largest category. Specifically, 22% occurred in contracting (public procurement) marking this as the highest areas3. This public financial corruption has led to the outflow of approximately 92.77 billion pesos since 2016 and the loss of 13.67 billion pesos worth of resources. Such corruption hinders the implementation of various public services, including infrastructure, education, and public policy development.
Current Efforts
Bogotá, Colombia’s capital, where numerous infrastructure projects are actively underway, is also exposed to the risk of corruption. Efforts to enhance transparency in the public infrastructure sector are crucial, especially given the active progress of large-scale transportation projects like TransMiCable, TransMilenio, and the First Metro Line of Bogotá (PLMB), as well as public infrastructure projects in education, welfare, and other areas. Local Colombian officials in Bogotá have implemented various initiatives to prevent corruption and promote financial transparency, utilizing digital technologies through various websites and citizen platforms such as CoST, Bogotá Cómo Vamos, SECOP, and SIIF.
1. CoST (Infrastructure Transparency Initiative)
CoST (Infrastructure Transparency Initiative) is a leading global non-profit organization dedicated to improving transparency, participation, and accountability in public infrastructure to deliver high-quality infrastructure that enhances quality of life and strengthens economies. CoST builds trust by disclosing data through data platforms and conducts independent reviews of infrastructure projects, which is known as the CoST assurance process. Bogotá mandates and formalizes the disclosure of key infrastructure information, including budget, contracts, and progress, according to CoST data standards, and applies an independent assurance process to all projects to ensure the suitability of budget execution and procedural transparency.
2. Bogota Como Vamos
Bogotá Cómo Vamos is a citizen-led urban monitoring system that regularly tracks and evaluates changes in Bogotá’s quality of life and municipal administration. It provides information to citizens through various annual reports, including the ‘Citizen Perception Survey (Encuesta de Percepción Ciudadana)’, the ‘Quality of Life Report (Informe de Calidad de Vida)’, and ‘City Council Monitoring Reports’. These materials offer evidence-based analysis to the media, academia, and policymakers, specifically identifying areas needing improvement.
3. SECOP (Sistema Electrónico para la Contratación Pública)
SECOP is Colombia’s electronic public procurement portal. It ensures transparency by publishing every stage of procurement: contract announcements, bidding documents, award results, and implementation status. This ensures fair competition and enables auditing by citizens and experts. All government agencies and local authorities are required to register with SECOP and upload their procurement processes to ensure contractual transparency. The general public can freely access information on who contracted with whom, for what amount, and which companies were awarded contracts, with data available for download in Excel format at colombiacompra.gov.co/secop.
4. SIIF
SIIF is an integrated financial management system under the Colombian Ministry of Finance that processes budget, accounting, and treasury functions on a single platform. It enhances internal control by reducing data entry errors through module-specific automation and implementing real-time approval procedures. The system also generates consistent financial reports, improving data interoperability between central and local governments, thereby enhancing fiscal efficiency and minimizing the potential for budget misuse or procedural violations. However, its primary purpose is for internal use by public institutions, so it does not provide a separate visualized dashboard of all data for general citizens, limiting its effectiveness in promoting transparency.
5. IDU Visor de Proyectos
The Urban Development Institute (IDU) is a public agency responsible for urban development, design, and construction in Bogotá, planning roads, pedestrian areas, bike paths, and eco-friendly transport networks. The IDU Visor de Proyectos system provides a visual, map-based portal that displays ongoing projects in Bogotá on a map and allows users to view specific information for each project. This enables citizens to easily locate projects by their status and access linked contract-related information for each project.
Current Limitations & Need for New Solutions
Despite the transparent disclosure of public procurement contracts, budget allocations, budget execution, and public infrastructure project information across various governmental websites, there still persist several limitations. First, financial and contracting data are dispersed across multiple platforms, making it difficult to access them in one platform. Second, information formats such as legal documents, datasets, and reports are difficult for citizens to interpret at a glance. Third, real-time tracking of financial flows in public procurement contracts is limited, restricting transparency and accountability. These limitations restrict citizens’ ability to track funding flows and understand project stages, delays, and where those delays originate. This undermines their ability to act as fair watchdogs and evaluators, ultimately weakening public trust in government transparency.
Problem Definition
How might we use advanced digital solutions to ensure full traceability of public finance flows to combat corruption?
How can the City follow the flow of the finances dedicated to a particular contract?
How can they follow the path from the approval of the budget, through the Finance department, to the implementing agency, and on to the private contractor?
Our Goals
To address these challenges, our tasks (strategies/goals) are as follows:
Integrate financial data, currently dispersed across multiple platforms, into one single platform for easy and convenient access.
Ensure real-time and accurate tracking of financial transactions of the project, enabling citizens, experts, and administrators to monitor and verify them.
Provide a visualized dashboard of public works and contract-related data that is easily understandable for suppliers, administrators, and citizens as well.
Ultimately, this aims to guarantee full transparency and traceability in public works contracts and public financial flows, thereby enhancing citizens’ trust in Bogotá’s administration.
Overview of Our Solution
The “Y” in Y-Bridge represents both “Why?”, the critical question of why we must solve this problem, and “Yonsei”, symbolizing the origin point of connection.
The term “Bridge” carries three layers of meaning:
A bridge connecting citizens and public finance: Transforming invisible budget flows into accessible information, thereby building a bridge of trust across corruption and distrust.
A bridge connecting present and future: Replacing opaque, outdated governance practices with blockchain- based digital innovation to establish sustainable financial systems for the future.
HowY-BridgeWorks
Y-Bridge integrates with public infrastructure contract data from SECOP, which publicly discloses information such as contract announcements, bidding documents, award results, and implementation statuses. Using the Partisia blockchain, each infrastructure contract is stored as a unique block. Every stage of the project, along with each payment process, is logged with a timestamp, enabling continuous real-time tracking.
Step-by-Step Process
1. Contract Upload
When a public procurement bid begins in SECOP, and Once a supplier is selected, the new contract is uploaded to SECOP.
2. Data Collection
Through SECOP’s API (which provides JSON data), Y-Bridge parses and transforms contract information into a structured format suitable for its frontend interface. This logic enables the processing of all contract data for display on Y-Bridge.
3. Verification
In the Y-Bridge “administrator Tab,” administrator review automatically populated contract details, input any missing information for payment, and confirm the contract.
Access to Y-Bridge is controlled by RBAC (Role-Based Access Control).
Supplier Tab: Used by suppliers to upload evidence of contract fulfillment.
Administrator Tab: Administrator review evidence, confirm or reject claims, and approve payments. Citizen Tab: Provides transparent, read-only access to project and contract information for the public.
When suppliers upload completion documents, administrators are alerted. If verified, approval triggers the blockchain smart contract update and initiates the bank transfer via API. Payment details—amount, payer, receiver, timestamp—are instantly logged and displayed in the frontend system.
4. Blockchain Recording
Once confirmed by the administrator, the contract data is stored as a new block (smart contract) with a unique ID on the blockchain.
Stored contract data in blockchain as follows:
Upload date/ time linked to SECOP
Process ID & number
Contract title
Contract description
Contract status
Contract category
Contracting authority and supplier details(Names, signatures, and timestamps of both parties)
Bank account information of authority and supplier
Total contract value
Payment Conditions
Contract start date and expected end date
SHA-256 hash(One-Way Encryption) of the signed contract PDF
Hashes of key supporting documents (e.g., compliance reports)
Most items are parsed directly from SECOP data; missing items are manually input by administrators
5. Repeating the process for each stage
Y-Bridge monitors for 7 types of anomalies, flagged on the frontend with a bell icon:
Single-bid contracts (lack of competition).
Excessively high share of direct contracts.
Contracts exceeding one year without justification (abnormal long-term contracts).
Multiple simultaneous contracts awarded to the same supplier (risk concentration).
Excessive delays in payments despite confirmed fulfillment.
Incorrect sequencing of procedures (e.g., payments made without confirmation).
Discrepancy between contracted and disbursed payment amounts.
Types 1–4 replicate Bogotá’s existing Early Warning System (Señales).
Types 5–7 extend monitoring to financial flow tracking anomalies.
Detection methods: Rule-based detection: Types 1, 3, 6, 7 / Machine learning-based detection: Types 2, 4, 5, using Amazon Lookout for Metrics (an AWS service that automatically detects statistical anomalies).
6. Completion
Once the final conditions are met, the smart contract status updates to “Completed”, recording the completion date. The frontend displays the updated project status and automatically generates a summary report and supporting documents.
Additional Functions
1. Chatbot
An AI-powered assistant helps citizens query about contract data. The name of our chatbot is chat B. Chat B understands user questions and generates natural language responses by leveraging Large Language Models (LLM). With Retrieval Augmented Generation (RAG) technology that retrieves internal documents to provide real data to the LLM, coupled with a Vector Database for semantic-based similar document searches to guide accurate responses, the website’s chatbot helps citizens easily and accurately find desired information. Citizens can use the chatbot to easily search and summarize contract details, understand budget flows, and verify anomaly detections.
2. GPS-based Project Visualization
For public works contracts with physical locations that are currently underway (excluding public service-related contracts), projects are displayed on a map on the frontend. Clicking on a specific public works project on the map provides more detailed information about that project. Contract-related data and location information obtained from SECOP are sent to the Google Maps API, which then uses the Google Maps Geocoding API to obtain latitude and longitude coordinates for the addresses provided. A map is generated using the Google Maps API, and markers are placed at the obtained coordinates (an icon indicates if an anomaly is detected). A tab link is embedded to direct users to the Y-Bridge contract info tab when a coordinate is clicked.
Our Impact on the Community
The Y-Bridge project integrates Bogotá’s public financial data into a single unified platform, enabling real-time tracking of transactions and contract processes. This allows citizens, suppliers, and administrators to transparently access and verify information, while the visualized dashboard helps make complex financial flows easier to understand. In particular, its anomaly detection feature and citizen online board encourage active civic participation and social oversight, strengthening accountability and transparency in the execution of public works. Ultimately, this approach enhances financial transparency in Bogotá and helps restore citizens’ trust in the city administration. Furthermore, the Y-Bridge project is closely aligned with the UN Sustainable Development Goal (SDG) 8, “Decent Work and Economic Growth.” By ensuring transparency in public works and contract execution, it reduces losses caused by corruption and allows more efficient use of public funds, thereby reinforcing Bogotá’s foundation for economic growth. Y-Bridge goes beyond being a mere technological solution — it has the potential to evolve into a sustainable, participatory governance model where citizens and government jointly monitor and manage public financial flows. In the long term, this model could be expanded nationwide, becoming a key reference for Colombia’s anti-corruption and economic growth strategies.
Business Model
Through Y-BRIDGE
Stakeholders & Their Benefits
Bogota gains revenue from Y-Bridge’s banner advertisements as well as from the sales and licensing of the Y-Bridge solution.
Suppliers benefit through improved efficiency and enhanced trust.
Administrators also experience greater efficiency and strengthened trust.
Citizen can obtain reliable information and have opportunities to participate in national administration.
Banks earn revenue from transaction fees.
External Agency ensure efficiency and stability by making use of benchmarking.
Tech companies receive payments from the Bogota government.
Team Information
Challenge 6: Financial transparency in Public Works Y-Bridge Yonsei University | Seoul, South Korea | YA-KR-1
If you have any ideas or feedback, it would be greatly appreciated as we work to develop our solution. Thank you!
