Secure data transmission utilizes technologies like encryption, SSL/TLS protocols, and VPNs. Encryption converts data into a secure format, making it unreadable without the decryption key. SSL/TLS adds a layer of security by establishing a secure connection over the internet, often seen in HTTPS. Additionally, VPNs create a private network over the public internet, protecting the transfer of data. Together, these technologies ensure that sensitive information remains confidential and integral during transmission.