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Koledzy, kto się bawi w sumy kontrole przy archiwizacji zdjęć . Jeśli ktoś bardzo się boi, to kopia na dysku i płycie wystarczy, ostatecznie na 2 płytach.

oj tam oj tam

Czym się wg. Ciebie różni CRC32 od MD5?

Mało prawdopodobne, ale możliwe. Dlatego używa się od ponad 10 lat co najmniej MD5.

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They each implement a different cryptographic hash function, and each hash function does generate a different sized hash. The main difference between the three functions you've shown here is that sha1 and md5 are actually meant to be cryptographically secure. crc32 (crc stands for cyclic redundancy check) function is not a crypto function and is meant to generate a hash that will be used to check the integrity of a file (mostly to determine if it was corrupted during download).

Just a side note: Please don't use md5 or sha1 for any real crypto work (such as hashing passwords). These are both terribly broken (just ask evernote or any of the other companies burned by using this old algorithm). Instead use the php crypt() function and use the SHA-256 or SHA-512 (better than 256), or blowfish. And always salt your hashes...

http://stackoverflow.com/questions/1...-crypto-on-php

MD5 is a one-way-hash algorithm. One-way-hash algorithm are often used in cryptography as they have the property (per design) that it's hard to find the input that produced a specific hash value. Specifically it's hard to make two different inputs that gives the same one-way-hash. Those they are often used as a way to show that a amount of data have not been altered intentionally since the hash code was produced. As the MD5 is a one-way-hash algorithm the emphasis is on security over speed. Unfortunately MD5 is now considered insecure.

CRC32 is designed to detect accidental changes to data and are commonly used in networks and storage devices. The purpose of this algorithm is not to protect against intentionally changes , but rather to catch accidents like network errors and disk write errors etc. The emphasis of this algorithm is those more on speed than on security.

http://stackoverflow.com/questions/1...for-common-use