(1) Hackers are people who create and modify computer software and computer hardware, including computer programming. Hackers are software designers and programmers who build elegant and beautiful programs and systems.
Hackers (or computer experts) refer to people who develop and redesign computer software and hardware, including computer programs. Hacker is also a software designer and developer, who can develop first-class and beautiful programs and systems.
(2) An attack is an attack on a computer system or network, and it is the result of deliberate intelligent behavior. Such as violent attack, dictionary attack, denial of service attack, replay attack, piggyback, infiltration and destruction.
An attack is a deliberate and intelligent attack on a computer system or network. For example, brute force cracking, dictionary cracking, "denial of service" attacks, replay attacks, binding attacks and infiltration attacks or sabotage.
(3) Network scanning is the use of computer networks to collect computer system information, which can be used for system maintenance, security assessment and investigation, and attacks.
Network scanning is the use of computer networks to collect computer system information, which may be used to maintain the system, evaluate and detect the safety factor of the system, and even attack the system.
(4) The message encrypted by the sender with the public key of the recipient can only be decrypted with the counterpart private key of the recipient.
The information encrypted by the sender with the public key of the receiver can only be decrypted with the personal key corresponding to the receiver.
(5) Until modern times, cryptography almost refers to encryption, that is, the process of transforming ordinary information (plaintext) into something difficult to understand; This is a cipher text. Decryption, on the other hand, changes from incomprehensible ciphertext to plaintext.
Until today, cryptography involves almost all encryption. Encryption is the process of transforming ordinary information (plain text information) into difficult or unreadable information. This unreadable information is called cipher body. On the other hand, decryption converts complex password text into plain text.
(6) In cryptography, the cryptographic hash function is a hash function with some additional security attributes, which makes it suitable to be used as a primitive in various information security applications, such as authentication and message integrity.
In cryptography, cryptographic hash function refers to having specific additional security attributes as the basis of various information security applications, such as identity authentication and information integrity.
(7) Symmetric key encryption refers to an encryption method in which the sender and the receiver share the same key (or, less commonly, their keys are different, but they are related in an easy-to-calculate way).
Symmetric key encryption refers to an encryption method in which the sender and receiver of information can use the same key (or, in rare cases, they use different keys, but their correlation can be simply calculated).
(8) Besides encryption, public key encryption can also be used to implement digital signature schemes. Digital signature reminds people of ordinary signature; They all have one feature, that is, it is easy for users to make, but it is difficult for others to forge.
Besides encryption, public key encryption can also be used to implement digital signature schemes. Digital signature is similar to ordinary signature, which is simple for users and difficult for others to imitate.
translation from Chinese to English
(1) Active attack will change the state and service of network system. Active attacks include trying to prevent or destroy protection mechanisms, introducing malicious code, and stealing or tampering with information. Active attacks may lead to data leakage and dissemination, or lead to denial of service and data tampering, including most unauthorized users trying to enter the remote system through abnormal means and normal means.
Active attack will cause the change of network system state and service. Active attacks include trying to prevent or destroy protection mechanisms, introducing malicious code, and stealing or tampering with information. Active attacks may lead to data leakage or dissemination, or lead to denial of service and data tampering, including most unauthorized users trying to access remote systems through ordinary or unusual methods.
(2) Generally, a complete attack process is to hide yourself first, and then carry out pre-attack detection to detect various attributes of the target machine and the attacked situation; Then take corresponding attack means to destroy, and after achieving their own goals, the attacker will delete the log of his behavior in the target system.
Generally speaking, a complete attack process is that the attacker hides himself first, and then begins to detect before the attack, detecting various attributes of the target machine and understanding which conditions are conducive to the attack; Then take appropriate measures to carry out sabotage attacks. After success, the attacker will delete his own operations in the target system log.
(3) Denial of service (Dos attack for short) refers to the attempt to prevent legitimate users from using the network services provided by the attacked target system by illegally monopolizing the services of the attacked target system. The most common denial of service attack is that the attacker consumes all the available bandwidth of the victim's network by generating a large number of packets flowing to the victim's network.
Denial of service (Dos) refers to an attempt to illegally invade the service of the targeted system, making it impossible for legitimate users to use it. The most common denial of service attack is that the attacker generates a large number of network packets and makes them flow to the victim's network to consume all the available bandwidth of the network.
(4) A basic principle of modern cryptography is that all secrets exist in keys. It means that when designing an encryption system, it is always assumed that the cryptographic algorithm is public, and what really needs to be kept secret is the key. This is because encryption algorithms are easier to leak than keys.
One of the basic principles of modern cryptography is that all secrets are kept in keys, which means that when designing encryption systems, designers always assume that cryptographic algorithms are public; What really needs to be protected is the key. Because encryption algorithms are more easily leaked than keys.
(5) The password of symmetric cryptosystem needs to be transmitted from the sender to the receiver through a secure password channel. The advantages of this cryptographic system are high security and high encryption speed. Disadvantages are: with the expansion of network scale, key management becomes a difficult point; Unable to solve the message confirmation problem; Lack of ability to automatically detect key leakage.
The key of symmetric cryptosystem needs to be sent by the sender to the receiver through secure access. The advantages of cryptography are: high security and fast encryption speed; Disadvantages are: with the growth of network scale, key management becomes difficult; Unsolvability of message confirmation difficulty; Lack of ability to automatically detect key leakage.
(6) Public key cryptography is also called asymmetric key cryptography. Every user who uses public key cryptography has two keys: an encryption key and a decryption key. These two keys are different, so it is not feasible to obtain the decryption key from the encryption key on the computer. Every user's encryption is public (therefore, the encryption key is also called the public key).
Public key encryption is also called asymmetric key encryption. Every user who uses public key encryption has two keys: encryption key and decryption key. These two keys are different, in addition, it is not feasible to obtain the decryption key from the encryption key on the computer. Each user's encryption key is public (therefore, the encryption key is also called the public key).