Praveen's personal website

Praveensankar Manimaran

Praveensankar Manimaran is a Research and Engineering Scientist at Zoho, India, working on Applied AI and Language Technologies. Praveen is about to complete his PhD at the University of Oslo, Norway, focusing on Verifiable Credentials and Zero-Knowledge Proofs. His research interests are AI, Verifiable Credentials, Privacy-Preserving Protocols, Zero-Knowledge Proofs, and Applied Cryptography. As part of the PhD, Praveen designed research projects, identified challenging research problems including privacy issues in VCs revocation, developed novel solutions, and built prototypes to showcase the feasibility. Praveen's expertise includes identifying and solving non-trivial research problems that directly impact the industry use cases. In addition, Praveen has experience in project management, effective communication and coordination of tasks among team members, and time management.

github linkedin google scholar ORCID Resume

email : praveema@ifi.uio.no

Work Experience

Research and Engineering Scientist

Zoho Corporation Pvt. Ltd., Chennai, India. (Dec 2025 - Current)

Responsible for designing systems to solve problems in the domains of Applied AI and Language Technologies

PhD Research Fellow

University of Oslo, Norway. (Oct 2020 - Oct 2024)

Research in Verifiable Credentials, Zero-Knowledge Proofs, and Blockchain Technologies
Worked on privacy issues in VCs's revocation and verification, and developed solutions using techniques such as Zero-Knowledge Proofs, Merkle Tree Accumulators, and BBS Signatures.
Implemented prototypes to showcase the practicality of the solutions.
Published research papers in top venues: Computer Science Review, and IEEE Blockchain.
Installed and maintained Norway's EBSI pilot node
Supervisors: Roman Vitenberg (Homepage), Leander Jehl (Homepage)
Advisors: Thiago Garrett (Homepage), Mayank Raikwar (Homepage), Arlindo F. Conceição (Homepage)

Summer Research Intern

National Institute of Technology Calicut, Kozhikode, India. (May 2019 - July 2019)

Studied about Software Defined Networking, mininet simulator, Named Data Networking and usage of NDN in VANET
Designed and developed Intrusion Detection System for NDN Based VANET

Software Engineer

Accolite Software India Pvt. Ltd., Bangalore, India. (July 2016 - March 2017)

Worked on the web development
Language - C#, Javascript, Web framework - ASP.NET MVC, backend technology - ASP.NET, frontend technology - Jquery and AngularJS, database - Microsoft SQL Server
Worked on web development for British Telecommunications through Accolite

Software Engineer Intern

Accolite Software India Pvt. Ltd., Bangalore, India. (January 2016 - April 2016)

Worked on the web development
Language - C#, Javascript, Web framework - ASP.NET MVC, backend technology - ASP.NET, frontend technology - Jquery and AngularJS, database - Microsoft SQL Server
Learned about web development in general and studied ASP.NET and Basic javascript for developing websites
Studied about 3 Layer architecture in ASP.NET

Education Details

PhD - Informatics

University of Oslo, Norway. (October 2020 - Present)

Research in Verifiable Credentials, Zero-Knowledge Proofs, and Blockchain Technologies

M.Tech. - Computer Science and Engineering

National Institute of Technology Puducherry, karaikal, India. (July 2018 - June 2020)

CGPA - 9.82 / 10 (gold medal)

B.E. - Computer Science and Engineering

PSG College of Technology, Coimbatore, India. (July 2012 - May 2016)

CGPA - 7.69 / 10

Research Adoption

EBIP: Secure Privacy-Preserving Revocation of Verifiable Credentials

Presents a security vulnerability in EBSI's Dynamic Status List, a revocation protocol for verifiable credentials that addresses holder's privacy.
Adopts a ZKP-based revocation protocol that I developed along with my colleagues during my PhD.

https://hub.ebsi.eu/ebips

Publications

zkToken: Empowering Holders to Limit Revocation Checks for Verifiable Credentials

The 26th Privacy Enhancing Technologies Symposium (PETS), under review.

Formalizes the privacy of holders in the verifiable credentials system.
Proposes zkToken, a revocation protocol that uses a custom-built Zero-Knowledge Proof circuit to address the privacy issue.
zkToken outperforms existing protocols in terms of required bandwidth for issuers and holders.

https://arxiv.org/html/2509.11934v1

Decentralization Trends in Identity Management: From Federated to Self-Sovereign Identity Management Systems.

Computer Science Review (Volume 58, November 2025, 100776)

Studies Federated and Self-Sovereign Identity systems from a conceptual point-of-view.
Proposes a generic framework for Identity systems and analyses the architectures and workings of (a) IOTA Id, (b) Indy, and (c) eIDAS v1.0
Highlights differences in decentralization and privacy strategies across these systems.

https://www.sciencedirect.com/science/article/pii/S1574013725000528

Prevoke: Privacy-Preserving Configurable Method for Revoking Verifiable Credentials

2024 IEEE International Conference on Blockchain (Blockchain)

Prevoke presents key privacy challenges in the revocation protocol and proposes a novel solution.
Prevoke keeps track of the revocation status of VCs using a Bloom Filter, and a Merkle Tree Accumulator. These data structures are stored in a DLT using a Smart Contract and updated during revocation of VCs.
Prevoke proposes a novel two-phase verification technique which enables efficient and fast verification of almost all valid VCs. Only revoked VCs and handful of valid VCs go through expensive verification

doi: 10.1109/Blockchain62396.2024.00053

Projects

Untrace - Implementation

University of Oslo, Norway. (August 2024 - present)

This Implementation demonstrates the working of Untrace in a sand-boxed environment.
Untrace is the implementation of the protocol that we developed to address the problem of holder's traceability in Verifiable Credentials system
We built a custom ZKP-circuit based on groth16 ZKP scheme using the gnark library.
This implementation consists of a) standard entities (Issuer, Holder, and Verifier), b) a Smart Contract, c) a mock VC data model based on W3C Specifications.
Workflows: 1) issuance, 2) revocation, 3) VP construction and sharing, and 4) VP verification
Benchmarks: benchmarked the performed of Untrace and IRMA's revocation technique
Results: Untrace outperforms IRMA's protocol in terms of the required bandwidth for holders and issuers
Languages: Golang, Solidity, and Python

The GitHub repository will be shared upon request, as the research paper is not yet published.

Prevoke - Implementation

University of Oslo, Norway. (August 2023 - August 2024)

This Implementation demonstrates the working of Prevoke in a sand-boxed environment.
This implementation consists of a) standard entities (Issuer, Holder, and Verifier), b) a Smart Contract, and c) a mock VC data model based on W3C Specifications.
Workflows: 1) issuance, 2) revocation, 3) VP construction and sharing, and 4) VP verification
In addition, Smart Contract is deployed on a Private Blockchain using Ganache, hosted in NREC.
The entities are hosted as servers and geographically distributed using NREC.
Results: We analyzed the performance, latency, and cost of Prevoke for different workloads.
Languages: Golang, Solidity, and Python

github link

Other Activities

Skills

Programming Languages:  Golang, Solidity,
Expertise: Verifiable Credentials, Blockchain, Self-Sovereign Identity, Web3

Achievements

Scored 96.03 Percentile in Computer Science, GATE 2018
Scored 98.02% in HSC exam, 2012
Scored Centum in Computer Science, HSC exam, 2012
Scored 97.80% in SSLC exam, 2010
Scored Centum in Maths and Science, SSLC exam, 2010

Teaching work

Teaching Assistant - IN5420/IN9420: Distributed Blockchain Technologies

University of Oslo, Norway. (Spring 2022, Spring 2023)

Teaching Assistant - IN5020/IN9020: Distributed Systems

University of Oslo, Norway. (Autumn 2022, Aumtum 2023)