Practical Internet of Things Security - Second Edition

Encryption and decryption

Encryption is the cryptographic service most people are familiar with as it is used to so-called scramble or mask information so that unintended parties cannot read or interpret it. In other words, it is used to protect the confidentiality of the information from eavesdroppers (whether observing your communications or attempting to read your stored data), and to only allow it to be deciphered by intended parties. Encryption algorithms can be symmetric or asymmetric (explained shortly). In both cases, a cryptographic key and the unprotected data are input to the encryption algorithm, which encrypts the confidential data. Once in this state, it is protected from eavesdroppers. The receiving party uses a key to decrypt ...