In digital security, what does nonrepudiation mean?

Nonrepudiation is a key concept in digital security that ensures that a sender can be held accountable for the transmission of a message or the execution of a transaction. It means that once a message has been sent, the sender cannot deny having sent it. This is particularly crucial in scenarios involving legal contracts or critical transactions where accountability is vital.

Nonrepudiation is typically achieved through cryptographic methods, such as digital signatures, which authenticate the sender's identity and provide proof that the message has not been altered in transit. This assurance protects parties from disputes and provides evidence of actions taken, thereby fostering trust in electronic communications.

In contrast, the other options do not accurately represent the concept of nonrepudiation. The focus on reading messages, altering content, or restricting access speaks to different aspects of data integrity and confidentiality rather than the sender's accountability for their actions.