Non-repudiation

(OBJ 1.2)

Focused on providing undeniable proof in the world of digital transactions
Security measure that ensures individuals or entities involved in a communication or transaction cannot deny their participation or the authenticity of their actions
Medieval example: King using signed rings to sign letters so that it is undeniable that the king wrote that letter

Considered to be unique to each user who is operating within the digital domain
Created by first hashing a particular message or communication that you want to digitally sign, and then it encrypts that hash digest with the user’s private key using asymmetric encryption
- This allows the digital signature to ensure that a piece of information, whether it's an email or a transaction, originated from a stated source and hasn't been altered during its transit
- If someone attempts to refute their involvement in the digitally signed transaction, the signature serves as undeniable proof that they actually sent that and the integrity of that transaction hasn't been changed since they use their private key to create that digital signature, and that digital signature is made up of an encrypted hash digest.

To confirm the authenticity of digital transactions
- It is important that a system has the capability to guarantee a transaction or communication's authenticity is there to ensure that your users can't state they didn't perform a certain action.
- You really can't fake a digital signature because only they have their private key that's going to be used inside of that digital signature.
To ensure the integrity of critical communications
- All parties involved can trust that the messages haven't been tampered with because any alteration would break the chain of undeniable proof.
- Since non-repudiation relied on digital signatures and digital signatures have hash values in them, these digital signatures are used to ensure not just non-repudiation, but also integrity.
To provide accountability in digital processes
- When every action has a digital stamp of authenticity attached to it, we can create a sense of responsibility and accountability among our users because their actions can be traced back to them without denial.