wavelink avalanche

6bit string combined together as the line coordinates of the s box, the remaining four bits as the column coordinates, for example, the first bit of the 010111 string is 0 sixth bit is 1, then the line coordinates is 01B column coordinates is 1011B namely 0xB, Each pair of coordinates of the s box can be obtained with 4 bits of data as shown:Finally, the output from the 8 s box is linked together in order to get a new 32bit string, and then a P-box transformation to produce a new 32bit string,

In a microservices architecture, the service is split into services according to the business, and the service and service can call each other (RPC), which can be invoked with Resttemplate+ribbon and feign in spring cloud. To ensure their high availability, a single service is typically deployed in a cluster. Due to network reasons or their own reasons, the service does not guarantee that 100% is available, if a single service problem, call the service will be a thread blocking, if there is a la

definitely be re-established;b)--initdb: Initialize the database, do not build, there is no need to establish;7, check the source legality, and package integrity;A) encryption type:Symmetric encryption: Encrypt and decrypt using the same keyPublic key encryption: A pair of keys, public key, private key, public key is implied in the private key, can be extracted, and publicly out;One-way encryption: extracting data signature;If the original data, the results will certainly be the same;

@ribbonclient,feign with @enablefeignclients.2. Depending on the location of the service, the Ribbon is declared on the @ribbonclient annotation and feign is used in the interface that defines the abstract method @feignclient declaration.3. In different ways, the ribbon needs to build its own HTTP request, simulate an HTTP request and then send it to other services using resttemplate, which is cumbersome.Feign has been improved on the basis of the ribbon, using interfaces to define methods of o

# cat /etc/shadow:Login Name: Login nameEncrypted passwd: encrypted passwordDate Password change: Password Last modifiedMinimum password Age: Minimum password lifeMaximum password Age: Maximum password lifetimePassword warning Period: Warning time to user when password is about to expirePassword inactivity period: grace period (Intermediate period of time before account is disabled after password expires)Account Expiration Date: Accounts disabled timeReserved field: Reserved fields# cat /etc/gsh

key cryptography seldom encrypts data for secret key exchange.　　One-way encryption: or hash encryption. PlainText cannot be obtained by ciphertext. Used to implement extract data signatures, each of which has unique signatures, such as fingerprint encryption. One-way encryption can be used to perform data integrity checks. The features include:1, non-reversible. That is, only plaintext can be obtained by the ciphertext, and cannot be obtained by cipher text.2,

password is paired, one for the private key (private key), and one for the public key, key starts locks.3, one-way encryption: Also known as hash encryption, fingerprint encryption, can only encrypt can not decrypt, used to extract data signatures, often used for data integrity check, it has two features: (1) Avalanche effect, is what we often say the butterfly effect, as long as there is a small change in the file, the output will have a great chang

-way cryptographic algorithms:1. As long as the data is the same, the encryption results must be identical2. No matter how large the data, the encryption result is fixed long output3. Avalanche (butterfly) Effect: The original information changes the slightest, the result of encryption is very different4. Non-reversibleCommon one-way encryption algorithm:MD5 (Message Digest 5): 128bit fixed-length output;Shal (Secure Hash algorithm) 160bit fixed-lengt

example of one-way encryption:The file that holds the user's password in Linux is called Shadow, if we cat/etc/shadow we will find that the first few formats in the ciphertext are similar: $8 bit ciphertext $ fixed length cipherThe reason for this is that Linux uses one-way encryption to encrypt the user's password, when the user logs in, the system encrypts the password entered by the user, and then compares it with the password fragment inside the/etc/shadow file to determine if the password

guaranteeing its security. Sha blocks the input stream by 512 bits per block (64 bytes) and produces 20 bytes of output called the Information authentication Code or information digest.The input message length of the algorithm is unlimited, the output is a 160-bit message digest. The input is processed in 512-bit groupings. SHA-1 is irreversible, conflict-proof and has a good avalanche effect.The digital signature is realized by hashing algorithm, th

different messages that do not produce the same message digest SHA-1 is a data encryption algorithm, mainly to receive a piece of plaintext, and then convert it into a cipher in an irreversible way, or simply to take a string of input code, and convert them to a short length, fixed number of bits of output sequence is the process of hashing values.The security of one-way hash function is that its operation process of generating hash value has a strong unidirectional nature. If the password

beginning of the hash input helps maximize the "avalanche" effect in the hashing algorithm.) Some other ways to enhance security are: 1, per page tokenNew tokens are used on each page, either through an HTML form or by using a cookie, and if a mismatch occurs, the entire session terminates. 2, before performing the important operation, requires two steps to confirm the operation Security is a big problem and the details are the most important. Th

) . Asymmetric encryption is more secure than symmetric encryption: Both sides of the symmetric encrypted communication use the same secret key, and if a party's secret key is compromised, the entire communication will be cracked. Instead of symmetric encryption, which uses a pair of keys, one for encryption, one for decryption, and a public key that is public, the secret key is stored on its own and does not need to be synchronized with the secret key before communication like symmetric enc

commands that affect the value of this field include: Useradd-g, Usermod-[a]gEncryption methodSymmetric encryption: Encrypt and decrypt using the same passwordPublic Key cryptography: each password appears in pairs, a private key is a public keyOne-way encryption (also known as hash encryption): The main feature code extraction, do data validationEncryption features1. Avalanche effect: Small changes in initial conditions can result in great changes i

Most of the Web sites currently using MySQL use Memcache as the key-value cache. Although such a structure is extremely popular, there are many successful cases, but too dependent on memcache, virtually let memcache become the root cause of failure: Memcache Data Consistency problem: When the MySQL data changes, if not timely and effectively clean out the outdated data, will cause data inconsistency. This is not desirable in the Web2.0 era, which emphasizes immediacy. The

integrity is not destroyed; If the signature is inconsistent, the data is corrupted and discarded directly.****************************************************************************Extension Description:01: The characteristics of different data (data fingerprint information) is not consistentindividual encryption algorithm features• Same as data input, signature information output must be the same• Avalanche effect, small input change, will cause a

encryption and decryption of messages.2. Characteristics of encryption Algorithm 2.1 encryption algorithmsymmetric encryption: encrypt and decrypt using the same passwordPublic Key cryptography:1) Each password appears in pairs, one for the private key (secret key) and one for the public key2) Public-key cryptography is seldom used to encrypt data, which is slower than the symmetric encryption algorithm to encrypt data 3 orders of magnitude, about 1000 times times the speedone-way encryption is

In the previous section, we discussed that symmetric encryption can solve the problem of communication confidentiality, but it cannot guarantee the integrity of the information.Then we introduce an algorithm-one-way encryption. One-way encryption, like human fingerprints, is unique.A to B when the information will be appended to the end of the one-way encryption results, B received later with the same one-way encryption algorithm, the calculation of the results of encryption and pass over the pa

the avalanche effect, that is, even if a byte in the string, the final hash value will have a greater impact. The only way we can think of is to add each character in the string, get it and sum, let sum as the hash value, such as SUM (AD) = A+d, but according to the ASCII Code table know A (+d) =b (98) +c (99), then a collision occurred, We find that the direct summation of the words will be very easy to collide, then what to do? We can zoom in on th

situation is that the real server is hashed on 232 as a node. We assume that only 4 servers (such as), and then a above the hot data, the result of a hang up, and then do data recovery, a data migration to B, then B need to withstand the a+b data, also can not bear, also hung .... Then continue the CD all hung up. This has resulted inAvalanche effect.An analysis of the causes of the avalanche effect above:If there is no hotspot data, the pressure on