Encryption Key
When talking about data encryption, an encryption key refers to the algorithm or cipher that will be used to secure the data. Algorithms can not run on their own; they need keys to tell them what to output after scrambling the data. A key tells the system what kind of transformation the text or data will undergo when it is encrypted.
One of the biggest issues with keys today is their size. A larger-sized encryption key will be harder to hack into than a smaller-sized key. In other words, larger keys are tougher to decrypt. These days, a key of an 80-bit size is considered to be the minimum size for adequate security using a symmetric encryption algorithm. More common are 128-bit keys, which are considered to be very strong keys that are difficult to break. There are even bigger sizes available, such as 256 bits.
Keys are vital to keeping data secret. In order to keep the data secret, however, it is necessary to keep the key secret as well. The key can unlock the encryption; therefore, if it is not secret, the encrypted data may as well not be secret either. Modern encryption methods rely on the secrecy of the key.
Choosing a key is equally important. A key must not be something that can be easily guessed. Keys are usually generated randomly in order to produce a code that is unlikely to be guessed by chance. Still, achieving a truly random key is one of the major challenges in encryption today.