The role of end-to-end encryption in data security is to ensure that information is securely transmitted from one endpoint to another without being readable by unintended parties. This encryption method protects data in transit by encoding it, thus ensuring that only the intended recipient can decrypt and access the information. It plays a critical role in maintaining confidentiality, integrity, and authenticity, particularly in communications over the internet. By mitigating risks associated with data breaches, end-to-end encryption contributes significantly to user trust and safeguarding sensitive information.