I was thinking about some characteristics of the activity we’re undertaking, which may be considered good or even essential in some circumstances, and ask if the characteristics have a name. They all concern the process of getting from clear text to cipher text and back again and with a consideration of transmission or storage. Any cipher text is for illustration and doesn’t represent an actual encryption.
1. The set of characters in the cipher text is guaranteed to belong to the same set of characters used in the plain text. So, for example, if the plain text is composed of upper case Latin characters, then so is the cipher text. Does that property of the encipherment process have a name? I guess there are distinctions between exactly the same set and taken from the same set.
2. The size of the cipher text is guaranteed to be no greater than the size of the plain text. So, for example, if the plain text is composed of ten characters, then the cipher text is guaranteed to be no longer. Does that property of the process have a name? Important for storage and transmission. Anything offering compression will be a special case.
3. The process of decipherment will recover from interruption and loss, or corruption of part of the cipher text during transmission or storage. Obviously the damaged part will be lost, but if the decipherment proceeds correctly after the damaged section. Does that characteristic have a name?