Confidentiality: This element is closely connected with privacy, which means unauthorized parties are restricted from accessing the data.
Confidentiality requires measures to assure that only authorized parties can access the information. Cryptography and Encryption methods can be taken as an example of an attempt to assure confidentiality of data transferred from one computer to another. Integrity: Integrity ensures that data is not tampered during or after submission. Data stored in systems, databases must be protected through access controls and there should be a procedure to change the stored data. Example of Integrity is 1) If a message is sent from the source to destination through an email and if it is modified during the transit then the email has lost its integrity 2) One-way hashes where a hash of a selective set of data is calculated at the source end and is sent along with the original message.
At the destination, the message obtained is calculated and is compared with the hash received. If both hashes are different, it means that the message has lost its value. Availability: Availability ensures that authorized people can access the data when needed. Data only has value if the authorized party can access it at the right times. Nowadays, denying access to data has become a pretty common attack. According to CIA triad, availability is connected to information security because adequate security rules protect system components and ensuring that information is available.
These days we have been seeing some of the issues like websites being taken down by DDoS attacks. The focus of DDoS attacks is to deny users of the website access to the resources of the website which in turn can be very costly downtime. Other circumstances that could head to lack of availability of necessary data may include accidents such as power outages, natural disasters such as floods, hardware failures, programming errors, human errors and malicious code. Non-repudiation: Nonrepudiation is a way of assuring message transition among parties through digital signature and encryption. Non-repudiation must be able to assure that someone cannot deny or contest the thing. Such type of issue normally seen in electronic communications where one party cannot be confirmed as the receiver or denies viewing or signing the document.
So, Non-repudiation is nothing but setting all measures in one place which will prevent one party from denying the information they received. Example: By sending mail through a guaranteed option, which expects the receiver to acknowledge receipt through their physical presence or signature.