Security is paramount in the Celer Network, which employs robust mechanisms to ensure the safety of off-chain transactions. This article examines the cryptographic techniques and security protocols that underpin Celer’s architecture. Advanced users will learn about the use of multi-signature schemes, fraud proofs, and the role of watchtowers in monitoring and securing off-chain state channels. We will also discuss the economic incentives that align participant behavior with network security, providing a comprehensive overview of how Celer maintains trust and integrity in its Layer-2 environment.