CommunicationCommunication links such as a connection between a website and a browser are commonly encrypted using a standard known as SSL (Secure Sockets Layer). Messages between a website and a browser may traverse vast physical distances and pass through many machines on the way. Encryption is intended to prevent anyone between the sender and receiver from accessing the data being sent.
Digital CertificatesDigital certificates are a means of confirming the identity of information services. An organization publishes its company name and a public key in a digital certificate issued by a certificate authority. If you encrypt a message with that public key, only the organization listed in the certificate should be able to decrypt that message with its corresponding private key. This is used to verify the identity of web sites by sending them a secret code encrypted with a public key from a certificate and testing if they are able to decrypt the message and send the secret code back to you. document proof that a transaction occurred and was authorized by a particular individual or company. This is known as non-repudiation. For example, if a customer presents a smart card and a password when they purchase something it is difficult for them to claim they didn't make the purchase. authentication protocols to test the identity of a smart card, device or information service. This is typically based on public key cryptography whereby a secret is encrypted with a public key to confirm that an entity is in possession of the corresponding private key.
FilesystemsA filesystem such as a hard drive in a laptop may be encrypted such that a password is required to access data.
DevicesDevices such as mobile phones may be designed to use encrypted data storage by default.
FilesA single file can be encrypted. This can be done in addition to file system encryption. For example, a password management application will may encrypt its data with a master password.
Conversion of information into an cryptographic encoding