Cryptography secures online transactions by encoding sensitive information, making it unreadable to unauthorized parties. Techniques, such as encryption and hashing, protect data integrity and confidentiality. For example, SSL/TLS protocols create secure connections between clients and servers, safeguarding credit card details and personal information during exchanges. Additionally, advanced cryptographic methods, including public-key cryptography, facilitate secure key exchanges for digital signatures. Overall, cryptography builds trust in digital commerce by ensuring data protection and user privacy.