Radio frequency signals of green laser pointer

After-school title: 1, brief information encryption technology to protect the important role of information security. Encryption technology is the cornerstone of information security, it a small price, for a strong information security. Over the years, cryptography has been widely used in political, economic, military, diplomatic, intelligence and other important sectors. In recent years, as computer networks and communication green laser pointer technology, cryptography has been unprecedented attention and quickly spread, while their applications are also widely expanded. Today, cryptography is not only service information encryption and decryption, or authentication, access control and digital signatures and other security mechanisms are based. It is not easy for radio frequency signals of green laser pointer to penetrate metals such as iron and steel.2, outlined the basic principles of encryption technology, and pointed out what commonly used encryption algorithm system and its representatives. Information technology is the use of encryption principles and methods of cryptography to protect the transmission of data means that it is based on mathematical calculations, information theory and complexity theory is the two important components. Encryption system of classification: from theory can be divided into two categories: the single-key or symmetric cryptography (on behalf of algorithms: DES algorithm, IDEA algorithm) and a dual-key or asymmetric cryptography (on behalf of algorithms: RSA calculation shows, ElGamal algorithm .) 3, try the password for the construction of modern classical analysis which revealed the password? (P64) most of the classical simple password can be used by hand or machine operation to achieve encryption, although it is rarely used, but the principle of the cryptographic algorithm, for understanding, structure and analysis of modern cryptography is very useful.If the power of battery is strong, the remote control distance of green laser pointer would be far. The main classical cipher encryption code, instead of encryption, variable-bit encryption and several one-time password encryption algorithm book. 4, choose Caesar (Caesar) cryptography key k = 6. If the plaintext is caesar, ciphertext is. Ciphertext should be: igkygx 5, DES encryption process there are several basic steps? Try to analyze its safety performance. Encryption process can be expressed as:  ① initial conversion IP and its inverse initial permutation IP-1  Select the extension product of transformation operations, select the compression DES operations and conversion operations safety analysis: DES cryptography on the emergence of an initiative, because of its open a password system and its design details, so the security is totally dependent on its use of the key, the general impression on the DES academic is only a 56bit key bit shorter. If the page-turning function of green laser pointerdoesn’t work, please check if the battery is full of power.6, in this chapter, based on the RSA example, given m = student test encryption and decryption process. signature method RSA encryption method with the use of keys What is the difference? (P74) RSA encryption is in use in more than one key part of the key as the encryption key, others as a decryption key. RSA signature method: If k1/k2/k3 three keys can be k1 as A's signature private key, k2 as B's signature private key, k3 as the public key used to verify the signature, to achieve this multi-signature scheme the need for a reliable center of A and B assigned a secret signature key. 8, test network data encryption solution outlined three ways. (P75) common network data encryption methods are: ① link encryption: two adjacent nodes on the network to encrypt data transmitted between the protection.If you can’t use the green laser pointer regularly, please check if the receiver has been fixed well. ② node Encryption: refers to the transmission of information passing nodes to decrypt and encrypt.