I believe you have already heard of AD hoc radio equipment. AD hoc communication, with its unique fusion and heterogeneous communication system, provides a variety of emergency environment and communication support options for many emergency industries, covering a variety of complex environmental applications such as maritime rescue, emergency fire fighting, disaster area rescue, oilfield mine operation communication and urban border local management.

For information security, encryption algorithm is one of the most prominent existence, in mesh AD hoc communication, the common encryption algorithm is divided into DES encryption algorithm and AES encryption algorithm, but in many industries have its application.

DES encryption algorithm

Data Encryption Algorithm (DEA) is a symmetric encryption algorithm, which was developed by IBM in 1972. DES uses a 56-bit key with additional 8-bit parity bits to produce a maximum 64-bit packet size. This is an iterative block cipher, using a technique called Feistel, in which an encrypted block of text is split in half. The loop function is applied to half of them with the sub-key, and then the output is "xOR" operation with the other half; And then you swap these two halves, and the process continues, but the last loop doesn't swap. DES uses 16 cycles, four basic operations using xOR, substitution, substitution, and shift operations.

DES as an earlier symmetric encryption algorithm, if DES uses a 56-bit key, the number of possible keys is 2 to the 56th power. However, with the improvement of computer system capability, the security of DES is also weakened with the improvement of computing power, but it is still relatively high in security. In January 1999, RSA data Security announced that its 56-bit DES attack had been carried out in 22 hours and 15 minutes by a group called the Electronic Frontier Foundation (EFF), using 100,000 computers on the Internet. In 1997, NIST issued a notice calling for a new data encryption standard to replace DES as a federal information processing standard. The new data encryption standard was called AES.