OnChainSentinel

A real-time fraud prevention platform that ingests blockchain transactions as streams, enriches them with behavioral features, and uses AI models to detect suspicious activity before settlement.

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OnChainSentinel

Real-Time Fraud Prevention for Blockchain Transactions

⚠️ The Problem

Blockchain enables instant, irreversible value transfer—but that same property makes fraud fast, scalable, and devastating. Wallet drains, phishing campaigns, and automated scam contracts propagate in seconds, long before traditional analytics can respond.

To unlock blockchain’s full potential as a trusted value medium, fraud detection must operate in real time, at network scale, and without compromising decentralization.

💡 The Solution

OnChainSentinel is a real-time, AI-powered fraud prevention platform that continuously analyzes blockchain transactions as streaming events, detects suspicious behavioral patterns, and delivers actionable alerts before fraud propagates.

By combining Confluent’s event streaming platform with Google Cloud’s AI and serverless infrastructure, OnChainSentinel brings enterprise-grade fraud prevention to decentralized systems.

🦾 Technological Implementation

OnChainSentinel is built as a cloud-native, event-driven system designed for low latency, horizontal scalability, and auditability.

✏️ Architecture Overview

Arhitecture

🛠️ Key Technology Choices

  • Confluent Cloud serves as the real-time backbone for ingestion, buffering, and replay of blockchain events
  • Flink AI performs windowed, behavioral feature engineering on live transaction data
  • Gemini AI provides managed, versioned fraud scoring with sub-second inference latency
  • Cloud Run enables stateless, auto-scaling microservices for inference and decisioning
  • BigQuery supports offline analysis, compliance auditing, and continuous model retraining

This architecture demonstrates production-quality integration between Google Cloud and Confluent partner services.

🎨 Design

OnChainSentinel is designed with clarity, trust, and usability as first-class principles.

🪄 User Experience

The platform provides a real-time dashboard that surfaces:

  • Live transaction streams
  • Fraud risk scores
  • Flagged wallets and alerts

Risk decisions are clearly classified as:

  • LOW
  • MEDIUM
  • HIGH

To support human decision-making, the system includes AI-generated, human-readable explanations (via Gemini) that explain why a transaction was flagged.

🪶 Design Philosophy

  • Minimal, security-focused interface
  • Clear separation between detection and enforcement
  • Explainability prioritized over black-box automation

The result is a system that can be adopted by wallet providers, exchanges, and dApp operators without requiring deep machine learning expertise.

💥 Potential Impact

Fraud remains one of the largest barriers to mainstream blockchain adoption. A minimalistic fraud user flow example is provided as a reference User fraud flow example

OnChainSentinel enables:

  • Wallet providers to protect users before funds are lost
  • Exchanges to intervene pre-settlement
  • dApps to detect abuse patterns in real time
  • Emerging markets to adopt crypto with greater confidence

Because the platform is chain-agnostic and event-driven, it can scale seamlessly across ecosystems and transaction volumes without architectural changes.

🌟 Impact Areas

  • Consumer protection
  • Financial inclusion
  • DeFi risk reduction
  • Institutional blockchain adoption

🔢 Measurable impact

Acording with Crystal Intelligence's recent article (September 2025), 22.7 billion dollars were lost in crypto due to fraudulent activity.

With our solution in place, OnChainSentinel could reduce that significantly, and even with an impact of just 1%, we are talking about millions in savings / unlost funds.

💎 Quality of the Idea

OnChainSentinel is not another static analytics dashboard or rule-based scanner. It works by being completly standalone solution, and the client just needs to query each time to have the latest data information. We can see the flow and how it will protect user funds. Your assets are safe with just one API call away Flow User with OnChainSentinel

🫆 What Makes It Unique

  • Behavioral fraud detection, not transaction-level heuristics
  • Streaming-first architecture, not batch analytics
  • AI-assisted explainability for trust and transparency
  • Blockchain-correct prevention model focused on pre-settlement alerting—not unrealistic on-chain blocking claims

It applies proven fintech fraud prevention techniques to blockchain—where they are most needed but rarely implemented correctly.

🏆 Why OnChainSentinel Stands Out

  • Designed for real-world deployment, not a demo-only prototype
  • Built on real partner technologies, not mock integrations
  • Addresses one of the most critical unsolved problems in Web3
  • Balances decentralization with security and trust

🎥 OnChainSentinel Presentation

Due to the fact that the deployment of such a solution will be high cost, we prepared the fallowing resources for your own deployment:

💬 Frequently Asked Questions

❓Q: Does OnChainSentinel stop transactions on blockchains?

📝A: No. OnChainSentinel provides a risk assessment of the wallet (address) that you want to transfer the funds to. So wallets, dApps, CEX or any transaction maker should first query the system to make sure the address is safe to transfer to. This query of the risk assesment it happens before the transaction is broadcast.

❓Q: Why does it need to be real-time, and why continuous streaming of the transactions?

📝A: Blockchains (crypto) produce transactions continuously, and each transaction has two or multiple parties. If you want to transfer to an address, even if that address has not done any transaction lately, all the parties with whom it interacts could raise its risk assessment. So basically, when we look at a transaction, we don't look just at the active parties that were involved in the transaction, but also at the overall accounts that it interacted with.

❓Q: Does OnChainSentinel apply to the traditional banking system?

📝A: No. The banking system works through an intermediate system, so transactions are not final like in blockchain; accounts are banned over traditional systems (this does not happen in crypto - even if you blacklist a wallet through a smart contract, a new one is ready in seconds, and apart from that, some tokens do not have a ban function). Even if Bob sends by mistake an amount to Alice in the traditional system, supposing that Alice does not want to return the amount, there are processes involved and laws and charges made by the bank of Alice that force her to return the amount. Over crypto transactions are final, and if Alice does not want to return the amount, then that's it.

❓Q: How is OnChainSentinel different than existing spam/scam systems ?

📝A: Existing scam/spam systems are looking at a transaction and checking it against a set of rules, and if the transaction is in that set of rules, then it is flagged as scam, along with the address, and it does not work in real time. Our systems work in real time, so we can detect fraud in real time, and apart from that, OnChainSentinel is not examining transactions based on a set of rules; instead, we analyze them based on patterns and behavior, and AI excels at identifying patterns or anomalies, as it is the underlying infrastructure. The result is a recommendation rather than an enforcement, and it simply means that you should take a second look before going further.

OnChainSentinel turns real-time data into real-time protection.

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