Checksum 一個良好的校正和演算法通常會對進行很小的修改的輸入資料都會輸出一個顯著不同的值

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https://en.wikipedia.org/wiki/Checksum

https://zh.wikipedia.org/wiki/校正和

 

A checksum is a small-sized datum derived from a block of digital data for the purpose of detecting errors which may have been introduced during its transmission or storage. It is usually applied to an installation file after it is received from the download server. By themselves, checksums are often used to verify data integrity but are not relied upon to verify data authenticity.

The actual procedure which yields the checksum from a data input is called a checksum function or checksum algorithm. Depending on its design goals, a good checksum algorithm will usually output a significantly different value, even for small changes made to the input. This is especially true of cryptographic hash functions, which may be used to detect many data corruption errors and verify overall data integrity; if the computed checksum for the current data input matches the stored value of a previously computed checksum, there is a very high probability the data has not been accidentally altered or corrupted.

Checksum functions are related to hash functions, fingerprints, randomization functions, and cryptographic hash functions. However, each of those concepts has different applications and therefore different design goals.

 

 

校正和（英語：Checksum）是冗餘校正的一種形式。 它是通過錯誤偵測方法，對經過空間（如通訊）或者時間（如電腦儲存）傳送的資料的完整性進行檢查的一種簡單方法。

電腦領域常見的校正和的方法有迴圈冗餘校正（CRC）、MD5、SHA家族等。

 

Checksum 一個良好的校正和演算法通常會對進行很小的修改的輸入資料都會輸出一個顯著不同的值