[Apologies if you got multiple copies of this invitation] The 3rd International Workshop on Blockchain Applications and Theory (BAT 2021) <http://emergingtechnet.org/BAT2021/index.php> in conjunction with The 8th International Conference on Software Defined Systems (SDS-2021) <http://emergingtechnet.org/SDS2021/> Gandia, Spain. December 6-9, 2021 *BAT 2021 CFP* A blockchain is a distributed ledger for recording transactions and/or data in a meaningful order, maintained by many connected nodes without a trusted central authority. Blockchain has a great potential to create new foundations for most distributed systems by efficiently establishing trust among nodes, especially in emerging networks. Such a fundamental technology to enable decentralization play an important role in a wide spectrum of topics such as Internet of Things (IoT), Cyber Physical Systems (CPS), edge computing, cloud computing, fog, mobile computing, social networking, wireless communication, vehicular network, and even more other fields. At the same time, there is a lack of fundamental study on the limitations of blockchain such as scalability, security, privacy, efficiency, availability and dependability. Hence, the development and deployment of blockchain-based systems and applications will likely exhibit new requirements and complicated challenges, which brings more open issues and exciting directions for research communities. The aim of this workshop is to bring together researchers and practitioners working in cloud computing, distributed systems, cryptography, security, and networking, from academia and industry, who are interested in the applications and theory of blockchains and related protocols. Researchers are encouraged to submit original research contributions in all major areas, which include, but not limited to: * Theories of blockchain and distributed ledger technology * Distributed data store for blockchain * Distributed transaction for blockchain * Distributed consensus and fault tolerance mechanism * Blockchain in cloud computing * Blockchain in mobile and edge computing * Deployment and feasibility study in emerging networks such as VANET, connected vehicles * Blockchain in Intelligent Transportation Systems (ITS) * Blockchain and Financial Networks * Blockchain in vehicular network * Blockchain in the Internet of things (IoT) * Blockchain in Cyber Physical Systems (CPS) * Blockchain in social networking * Blockchain in supply chain management * Blockchain in connected and autonomous vehicles * Blockchain in mobile cellular networks * Blockchain and governance/policy/regulation * Game theory and blockchain * Real-world blockchain-based system analysis and optimization * Experience papers with blockchain * Security, privacy and trust of blockchain * Decentralization, scalability, and security tradeoff * Simulation and performance evaluation techniques * Secure smart contract and chain code *Submission* Papers selected for presentation will appear in the SDS Proceedings, which will be submitted to IEEE Xplore for inclusion. Papers must be 6 pages max in IEEE format, 10pt font using the IEEE 8.5" x 11" two-column format, single space, A4 format. All papers should be in PDF format, and submitted electronically at Paper Submission Link. A full paper must not exceed the stated length (including all figures, tables and references). Submitted papers must present original unpublished research that is not currently under review for any other conference or journal. Papers not following these guidelines may be rejected without review. Also submissions received after the due date, exceeding length limit, or not appropriately structured may also not be considered. Authors may contact the Program Chair for further information or clarification. *Important Dates:* Submission Date: 20 Oct, 2021 (Firm and Final) Notification to Authors: 31 Oct, 2021 Camera Ready Submission: 10th November, 2021 Please send any inquiry to Emerging Tech. Network Team at: emergingtechnetwork@gmail.com