Perfect security block cipher

• Main Author: GAO SHENGFA
• Format: Patent
• Language: Chinese; English
• Published: 31.03.2020
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION

The invention discloses a block cipher which is unrelated to the computing power of an opponent and is perfect and safe. According to the cipher, the perfect security attribute of the block cipher isrealized by a key with an extremely short length, and even a two-bit cipher cannot be cracked. The provision of the perfect security block cipher overturns the argumentation proposed by the famous scientist Shannon about that only when the length of the secret key is the same as the length of the message, one cipher may have perfect security. Aiming at the defect of the safest one-time pad, the patent provides perfect security and strong perfect security theories, and designs and realizes three perfect security block ciphers: a 2n-bit perfect security block cipher, a bit transformation perfectblock cipher and a strong perfect security block cipher. The security level is equal to one-time pad, the algorithm simplicity degree is equal to one-time pad, the algorithm simplicity degree is irrelevant to the computing po