Secure Blockchain Transaction

International Journal of Computer Techniques–IJCT Volume 12 Issue 6, November 2025 Open Access and Peer Review Journal ISSN 2394-2231 https://ijctjournal.org/ ISSN :2394-2231 http://www.ijctjournal.org Page 410 Internet 1.71% Journal/ Publicatio n 2.29% Words < 14, 2.82% Quotes 0.22% Ref/Bib 8.53% The Report is Generated by DrillBit Plagiarism Detection Software Submission Information Author Name Greeshma.M.S Title Secure Blockchain Transaction Paper/Submission ID 4691599 Submitted by [email protected] Submission Date 2025-11-19 10:12:21 Total Pages, Total Words 11, 3225 Document type Others Result Information Similarity 4 % Sources Type Report Content Exclude Information Database Selection Quotes Not Excluded Language English References/Bibliography Not Excluded Student Papers Yes Source: Excluded < 14 Words Not Excluded Journals & publishers Yes Excluded Source 0 % Internet or Web Yes Excluded Phrases Not Excluded Institution Repository Yes A Unique QR Code use to View/Download/Share Pdf File 1 10 20 30 40 50 60 70 80 90 International Journal of Computer Techniques–IJCT Volume 12 Issue 6, November 2025 Open Access and Peer Review Journal ISSN 2394-2231 https://ijctjournal.org/ ISSN :2394-2231 http://www.ijctjournal.org Page 411 DrillBit Similarity Report 411 A A-Satisfactory (0-10%) B-Upgrade (11-40%) C-Poor (41-60%) D-Unacceptable (61-100%) SIMILARITY % MATCHED SOURCES GRADE LOCATION MATCHED DOMAIN % SOURCE TYPE 1www.readbag.com 1Internet Data 2www.bhumipublishing.com 1Publication 3Blockchain for Secure EHRs Sharing of Mobile Cloud based E-health Sys, by Nguyen, Dinh C. Pa2019 <1 Publication 4spvryan.org <1 Publication 5ve.org.ua <1 Internet Data 6adam.curry.com <1 Internet Data 7kth.diva-portal.org <1 Publication 8egyankosh.ac.in <1 Publication 9repository.up.ac.za <1 Publication 10 www.freepatentsonline.com <1 Internet Data 11 www.ijireeice.com <1 Publication International Journal of Computer Techniques–IJCT Volume 12 Issue 6, November 2025 Open Access and Peer Review Journal ISSN 2394-2231 https://ijctjournal.org/ ISSN :2394-2231 http://www.ijctjournal.org Page 412 TITLE: Secure Blockchain Transaction Authors: ANANYA.N ([email protected]) GREESHMA. M.S ([email protected]) PANCHAMI. G ([email protected]) VANDHANA. K.M ([email protected]) Guide: Rakshitha. P Assistant Professor, Department of Cybersecurity Sri Venkateshwara College of Engineering, Banglore-562157 Abstract - suspicious activity, the system In today’s world, most financial and personal transactions happen online. This makes data security a big concern. To address risks like data breaches, hacking, and identity theft, our project “Blockchain Secure Transaction” aims to create a dependable and decentralized system for secure digital payments. The system uses blockchain technology to ensure transparency and immutability in each transaction, eliminating the need for a central authority. The process starts with user registration, where details are securely stored along with a picture password for better recognition. During login, users must pass both the picture password and a biometric check. This ensures that only the account. Once verified, the user enters the dashboard, where transactions begin through Zero-Knowledge Proof (ZKP) for privacy-preserving verification. Every transaction is validated with smart contracts. If there’s any mismatch or automatically blocks or freezes the transaction. The backend uses Java, while Firebase stores user data securely, and 2 factor.in enables OTP-based authentication. The frontend interface, designed in React (app.jsx), allows smooth navigation across pages. By combining blockchain, smart contracts, biometric authentication, and ZKP, this project provides a secure and user-friendly platform that prevents unauthorized access and builds user trust in digital payment systems. Keywords - Blockchain, Secure Transaction, Zero Knowledge Proof (ZKP),Smart Contract, Biometric Authentication, Picture Password, Decentralized System, Data Privacy, Transaction Verification, Firebase Integration, 2 factor.in OTP Authentication why blockchain helps? – Blockchain contributes by increasing the security and trustworthiness of online registered user can access their International Journal of Computer Techniques–IJCT Volume 12 Issue 6, November 2025 Open Access and Peer Review Journal ISSN 2394-2231 https://ijctjournal.org/ ISSN :2394-2231 http://www.ijctjournal.org Page 413 using transactions. It stores data across numerous computers rather than relying on a single central server, making it difficult for one individual to alter or hack the data. Every transaction is added to an unchangeable chain of records and secured with robust encryption. Because of this, it is simple to monitor events and difficult for anyone to tamper with the system. Blockchain reduces errors and saves time by 3 smart contracts to run transactions automatically when specific conditions are reliability. This idea motivated the addition of biometric and image password authentication in the suggested system. In addition, Wang et al. (2025) also discussed how combining blockchain and cryptographic proofs could be used to provide tamper-proof digital records as a basis for secure financial transactions. Although these research papers emphasize privacy and security individually, the suggested Blockchain Secure Transaction project combines several approaches — met. Simply put, blockchain ensures that your data is trustworthy, transparent, and safe. ZKP, smart contracts, biometric verification, and picture passwords — into one decentralized platform. Such Literature Survey – integration offers high-level privacy in Multiple studies have aimed at strengthening digital transaction security by employing blockchain technology. Zhang et al. (2024) suggested a data exchange model based on blockchain with the inclusion of Zero-Knowledge Proofs (ZKP) to ensure user privacy while verifying. Their study showed how it was possible to verify transactions without exposing individual details. Likewise, Zhou et al. (2024) identified the implementation of ZKSNARKs for protecting identities in blockchain systems with a focus on conjunction with user convenience, solving deficiencies in previous research that tended to consider only a single layer of security. privacy-preserving techniques. authentication Liao and Zheng (2024) examined the safety of smart contracts and observed threats that would result in transaction malfunction or data compromise. Their results justify the implementation of strong smart contract verification, which is in line with the strategy in this project. Bamashmos et al. (2024) presented a two-layered multi-factor authentication model based on blockchain for IoT purposes, demonstrating how a layer of verification enhances system International Journal of Computer Techniques–IJCT Volume 12 Issue 6, November 2025 Open Access and Peer Review Journal ISSN 2394-2231 https://ijctjournal.org/ ISSN :2394-2231 http://www.ijctjournal.org Page 414 system with a 1 Proposed Design – project delivers a strong yet simple solution The system to be proposed aims to secure, privatize, and make online transactions more trustworthy through the use of blockchain technology. It begins with a straightforward and user-friendly registration, where users establish an account by providing information and choosing a picture password for visual identification. At login, the system crosschecks the picture password as well as the user's biometric information (such as a fingerprint or face recognition) to confirm that only the right persons can access their for secure digital transactions. System Design – The Blockchain Secure Transaction project system design emphasizes the development of a safe and hassle-free online transaction environment based on blockchain technology. The design consists of a number of interdependent modules that synergize to provide data privacy, authentication, and transaction integrity. It starts at the frontend layer, where the user accesses the web or mobile accounts. Once they are authenticated as users, they access a dashboard from where transactions can be initiated securely. Each transaction request undergoes a Zero-Knowledge Proof (ZKP) protocol, which verifies its authenticity without exposing sensitive information. The authentic data is then computed using a smart contract, which verifies automatically if the conditions for the transaction are met. If it all checks out, the transaction is noted as successful and recorded indefinitely on the blockchain ledger. But if there is any mismatch or unusual activity, the transaction is rejected or frozen to safeguard against abuse. The system also uses Firebase for storing user logs and credentials, and 2 factor.in for sending OTPs upon authentication. The whole design makes sure that every step — from registration to verification of a transaction — is conducted securely and openly. By coupling blockchain's resistance to alteration with user-level verification such as biometrics and image passwords, this interface created with React (App.jsx). The user can register by providing personal information and choosing a picture password here. At the time of login, the system authenticates both the picture password and biometric information to identify the user. It thus avoids any unauthorized access right from the start. After logging in, the customer is able to view the dashboard and carry out transactions. All the initiated transactions are subjected to a Zero-Knowledge Proof (ZKP) cycle that ensures its authenticity without showing private information. The smart contract layer automatically certifies the transactional conditions before it can proceed. If the conditions are properly met, the transaction is added as a block in the ledger of the blockchain so that it cannot be edited or deleted. If any abnormality is detected, the transaction is blocked or frozen forthwith. The backend of the system, implemented in Java, ties the frontend to the blockchain network. It also communicates with Firebase, where user data is safely stored, and 2 factor.in, where OTPs are sent for extra verification. International Journal of Computer Techniques–IJCT Volume 12 Issue 6, November 2025 Open Access and Peer Review Journal ISSN 2394-2231 https://ijctjournal.org/ ISSN :2394-2231 http://www.ijctjournal.org Page 415 information like name, phone number, This multi-layered architecture provides seamless communication among all components while ensuring a high degree of data security. Methodology – 1) User registration is where the user provides information and selects a picture password that is safely stored in Firebase. 2) Both the picture password and biometric authentication are needed to authenticate the user at login time. 3) After authentication, the user gets dashboard to view or trigger transactions. 4) All transactions go through a ZeroKnowledge Proof (ZKP) to verify without exposing private information. 5) A smart contract automatically validates the transaction rules before execution. 6) If valid, the transaction is recorded in the blockchain ledger to ensure transparency and immutability. 7) If any mismatch or suspicious activity is detected, the transaction These credentials are securely stored by the system in Firebase. This process provides each user in the system. Login Authentication: is blocked or frozen to maintain Returning users input their login details. system security. Algorithm – Begin the Process: The process starts when the application is opened by the user. The home page offers registration or login options into the system. User Registration: If the user is new, he or she provides 8 email, password, and a picture password. The system cross-checks with the saved data. In case login is unsuccessful, the user is sent back to the registration page. If successful, the system proceeds to the biometric verification step. Picture Password Authentication: The system uses a picture-password method for biometric-style authentication. During registration, the user selects a specific access to the a unique identity for International Journal of Computer Techniques–IJCT Volume 12 Issue 6, November 2025 Open Access and Peer Review Journal ISSN 2394-2231 https://ijctjournal.org/ ISSN :2394-2231 http://www.ijctjournal.org Page 416 pattern or area on an image, which is stored as their picture password. Dashboard Access: During login, after entering their normal credentials, the system displays the same image. The user must repeat the correct pattern to verify their identity. Correct Password If the user selects the correct pattern, the system confirms their identity and redirects them to the dashboard. (Insert Image: Correct Password Scenario) The user accesses the dashboard after successful authentication. 9 From this point, users can see their balance, transaction history, or create new transactions. Create Transaction: Incorrect Password If the pattern does not match the stored picture password, the system displays an “Incorrect Password” message and denies access. (Insert Image: Incorrect Password Scenario) User enters receiver address, transaction value, and currency type (Ether/Bitcoin). System creates a transaction request and sends it for confirmation. International Journal of Computer Techniques–IJCT Volume 12 Issue 6, November 2025 Open Access and Peer Review Journal ISSN 2394-2231 https://ijctjournal.org/ ISSN :2394-2231 http://www.ijctjournal.org Page 417 Zero-Knowledge Proof (ZKP) Validation: Before being processed, the transaction is authenticated via Zero-Knowledge Proof. This makes it possible to verify the legitimacy of the transaction without disclosing private user information. If ZKP validation is unsuccessful, the transaction is blocked immediately. 1. Valid Proof If the ZKP responses are correct, the system verifies the user and allows the transaction to proceed. 3. Account Unfreeze Procedure If the account is frozen, the user receives an email containing instructions and a secure link to initiate the unfreeze process. 4. Account Unfreeze Notification Flow The user’s wallet account is frozen due to a failed verification attempt the system automatically sends an email notification to the registered email address. The email contains an “Unfreeze My Account” button. Once the user clicks on this button, they are 5 redirected to complete the required verification process and regain access to their account. 2. Invalid Proof If the responses are incorrect, the system marks the activity as suspicious and immediately freezes the account to prevent unauthorized access. the login page, where they can International Journal of Computer Techniques–IJCT Volume 12 Issue 6, November 2025 Open Access and Peer Review Journal ISSN 2394-2231 https://ijctjournal.org/ ISSN :2394-2231 http://www.ijctjournal.org Page 418 Smart Contract Verification: The authenticated transaction then invokes traceability and accountability can be ensured. a smart contract. Implementation and Simulation – It automatically verifies conditions like available balance, valid recipient, and limits of the transaction. If all conditions are satisfied, the contract authorizes the transaction. Blockchain Recording: After authorization, the transaction information gets encrypted and recorded in a new block of the blockchain ledger. The deployment of the Blockchain Secure Transaction system centers around combining various security and blockchain technologies in the development of a decentralized, transparent, and tamperevident transaction platform. The system is deployed based on a multi-layered design, where all parts—from the frontend interface to the blockchain backend—are critical to privacy, authentication, and transaction integrity. Each block points to the prior one, which The system frontend is written in React guarantees immutability and transparency. Failure Handling: If there is any irregular behavior or discrepancy found during verification, the transaction is blocked or frozen. The user is alerted of the failed or suspicious attempt. Successful Transaction: If the transaction is successfully completed, a confirmation message is sent to the user and the transaction is permanently stored on the blockchain. End of Process: All actions are securely logged in Firebase for record and audit purposes so that (App.jsx), offering a user-friendly and interactive frontend for transaction operations, login, and registration. Users enter their details and create a picture password during registration, which improves memorability as well as visual verification. The frontend is linked to Firebase, a secure real-time database, where all user credentials, picture passwords, and verification information are securely stored. Firebase takes care of data synchronization and authentication management so that there is effective communication between the client and server. The backend is done with Java, which does the fundamental business logic, manages encryption of data, and communicates with the blockchain network. The Java code carries out user authentication, transaction checking, and communication with smart contracts run on the blockchain. Smart contracts are programmed to set up automatic conditions for accepting or declining transactions. These are selfexecuting computer programs on the