Detailed Instructions: In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Problem:In cryptography , a Feistel cipher is a symmetric structure used in the construction of block ciphers , named after the German IBM cryptographer ; it is also commonly known as a Feistel network .
Solution:
In cryptography , a Feistel cipher is a symmetric structure used in the construction of block ciphers , named after the German-born physicist and cryptographer Horst Feistel who did pioneering research while working for IBM ( USA ) ; it is also commonly known as a Feistel network .