This paper reviews the critical role of encryption techniques in securing financial data in fintech applications. It discusses various encryption methods, including symmetric, asymmetric, and hybrid encryption, and their strengths, weaknesses, and practical applications. Symmetric encryption, such as AES, is efficient for large data sets but faces challenges in key management. Asymmetric encryption, using key pairs like RSA and ECC, ensures secure communication without the need for key exchange. Hybrid encryption combines the benefits of both symmetric and asymmetric methods for enhanced security and performance. The paper also explores end-to-end encryption (E2EE) for protecting data privacy during transmission and data-at-rest encryption for securing stored financial information. Case studies on blockchain and cryptocurrencies, as well as mobile payment apps, highlight the practical implementation of these techniques. Challenges in key management, computational costs, and regulatory compliance are addressed, along with emerging trends such as post-quantum cryptography, AI integration, and privacy-preserving solutions. The paper emphasizes the importance of collaboration among stakeholders to ensure robust data protection and innovation in the fintech ecosystem.This paper reviews the critical role of encryption techniques in securing financial data in fintech applications. It discusses various encryption methods, including symmetric, asymmetric, and hybrid encryption, and their strengths, weaknesses, and practical applications. Symmetric encryption, such as AES, is efficient for large data sets but faces challenges in key management. Asymmetric encryption, using key pairs like RSA and ECC, ensures secure communication without the need for key exchange. Hybrid encryption combines the benefits of both symmetric and asymmetric methods for enhanced security and performance. The paper also explores end-to-end encryption (E2EE) for protecting data privacy during transmission and data-at-rest encryption for securing stored financial information. Case studies on blockchain and cryptocurrencies, as well as mobile payment apps, highlight the practical implementation of these techniques. Challenges in key management, computational costs, and regulatory compliance are addressed, along with emerging trends such as post-quantum cryptography, AI integration, and privacy-preserving solutions. The paper emphasizes the importance of collaboration among stakeholders to ensure robust data protection and innovation in the fintech ecosystem.