To implement a secure login and registration process in your eCommerce application, you need to follow several steps. Firstly, use HTTPS protocol to encrypt the communication between the user’s browser and the server. Secondly, employ strong password policies and enforce password complexity. Thirdly, implement measures such as email verification and CAPTCHA to prevent automated attacks. Additionally, incorporate measures like two-factor authentication and account lockouts to enhance security. It is crucial to store user passwords securely using hashing algorithms and salt values. Regularly update your software libraries and frameworks to patch any security vulnerabilities. Lastly, conduct frequent security audits and penetration testing to identify and address any potential weaknesses.