md5 | 易学教程

PHP different one way hashes for password security

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问题 I was wondering to hash the password in PHP using different methods available and the combination of them for more and more security. I was wondering if this would work..? $pass = "***"; $salt = "!@)#%%@(#&@_!R151"; $pass = sha1($pass.$salt); $pass = md5($pass); 回答1: Rather than that, you can use a stronger hashing algorithm like sha512 with combination of a strong salt and UserID : Do it like this: echo hash('sha512', 'MyPassword' . $StrongSalt . $UserID); SHA512 is actually SHA-2 for which

Possible to convert MD5 to SHA256?

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问题 I have a vBulletin Database with double MD5'd passwords and a salt, would it be possible to take the Password in the vBulletin database, convert them to SHA256, and then store them in a new database? Is there any real easy way to do this? My main and only reason, is to prevent users from having to create new accounts, and to stop using MD5. 回答1: Hashing algorithms are one-way i.e. They cannot be reversed unlike Encryption-Decryption algorithms. MD5() is a hashing algorithm , so is SHA-1 / SHA

Performance issues when looping an MD5 calculator on many files

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问题 I'm creating a program that checks files by comparing their MD5s to a DB of already checked MD5s. It loops through thousands of files, and I see that it uses a lot of memory. How can I make my code as efficient as possible? for (File f : directory.listFiles()) { String MD5; //Check if the Imagefile instance is an image. If so, check if it's already in the pMap. if (Utils.isImage(f)) { MD5 = Utils.toMD5(f); if (!SyncFolderMapImpl.MD5Map.containsKey(MD5)) { System.out.println("Adding " + f

Calculate SHA1 or MD5 hash in iReport

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问题 How would one calculate an SHA1 or MD5 hash within iReport at report execution? I need to compare a pre-calculated hash against a database driven field (string). Using iReport 2.0.5 (Old) and Report Engine is embedded into a commercial application. 回答1: I used iReport and Jasper Reports some years ago and I don't remember the details, but I remember that you could put in some way Java code to be evaluated. Using that feature you could calculate the MD5 in few lines: String encryptionAlgorithm

How to get a fast file Hashing algorithm for large files on a mobile device

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问题 prologue However one important discovery i make during testing the md5, adler32 and crc32 on a 100Mb file, is that strangely it take the same time. This can only mean one of two thing i guess, that on The Android device, the filesystem is the bottleneck and it cannot feed the algorithm fast enough, or i made a fundamental error implementing JNI, the later one i could live with. Hashing small files like images, mp3 and files under 10Mb take seconds using the MD5 algorithm. My problem is i have

MD5 algorithm Decryption in java [duplicate]

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问题 This question already has an answer here : Is it possible to recover message from MD5 and Java? [closed] (1 answer) Closed 6 years ago . Is it possible to decrypt the below code? below is my method where we are encrypting the String values. If it is decrypt able please guide me how to do that, as per my understanding MD5 algorithm is not decrypt able but for now my job is to find the way to decrypt it. Please provide your valuable opinion to get it done. public static String encryptPassword

MD5 Hash function in excel?

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I would like to convert a number of excel cells in my document from a serial number to the MD5 hash of that serial number. Is there a precompiled formula in excel that does that, or is my only option to do VBA. If VBA, how would I do it? HoLyVieR Some links in the question Password hash function for Excel VBA are now broken. Here is an updated version of the accepted answer on that question : You'll find an implementation for VB and VBScript here: http://web.archive.org/web/20080526064101/http://www.frez.co.uk/freecode.htm#md5 I believe it would be quite easy to port to excel. However someone

Is Md5 Encryption Symmetric or Asymmetric?

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问题 For my iPhone application, Apple wants to know if my password encryption (md5) is greater then 64-bit symmetric or greater then 1024-bit symmetric. I have not been able to find it online, so I am wondering if anyone knows the answer. In addition, is this considered an appropriate encryption technology for passwords, or should I use something different? Thanks for any help! 回答1: MD5 is a hashing function, thus by definition it is not reversible. This is not the case for encryption (either

MySQL MD5 SELECT

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This following query returned null. SELECT `email`, `password`, `salt` FROM `users` WHERE `password` = md5(`salt`+md5('123123'+`salt`)+'123123') AND `email` = 'xeka@xeka.ru' The following query returned 'd2b4312db21705dafd96df14f8525fef', but why? SELECT md5( 'Vwm' + md5( '123123' + 'Vwm' ) + '123123' ) This code returned '422ad0c19a38ea88f4db5e1fecaaa920'. $salt = 'Vwm'; $password = '123123'; echo md5($salt . md5($password . $salt) . $password); Do user authorization. How do I create a query to the database so that the first took SALT and SALT have this I did some MD5 function? SELECT md5

Calculate MD5 of a string in C++

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I have a nice example of memory mapped files that calculates the MD5 hash of a file. That works fine with no problems. I would like to change it to calculate the MD5 hash of a string. So the example is: (include #include <openssl/md5.h> to run this code, and also boost stuff if you want to run the one with the file) unsigned char result[MD5_DIGEST_LENGTH]; boost::iostreams::mapped_file_source src(path); MD5((unsigned char*)src.data(), src.size(), result); std::ostringstream sout; sout<<std::hex<<std::setfill('0'); for(long long c: result) { sout<<std::setw(2)<<(long long)c; } return sout.str()