What must a company implement to comply with Requirement 4 of PCI DSS?

To comply with Requirement 4 of PCI DSS, a company must encrypt the transmission of cardholder data across open and public networks. This requirement is essential because open networks, such as the internet, are susceptible to various types of attacks that can expose sensitive information. By encrypting data during transmission, the information is rendered unreadable to unauthorized users, thereby protecting cardholder data from interception and misuse.

The primary goal of this requirement is to establish a secure environment for the transmission of sensitive payment information, ensuring that only legitimate recipients can access and understand the data being sent. This measure helps to mitigate risks associated with data breaches and enhances overall data security while maintaining customer trust.

Other concepts like monitoring access, limiting physical access, and developing an information security policy are important components of a comprehensive security strategy but do not directly address the specific needs of data transmission encryption outlined in Requirement 4.