On Windows, I was used to installing a separate program for everything: one to view images, one to browse PDFs, and another to calculate a file’s MD5 or SHA1. On Mac OS X, you don’t have to go through all that trouble! If you want to calculate the MD5 or SHA1 checksum of a file, there is a built-in tool for it. ...
Recently I was writing a password generator and needed to compute an MD5 hash. In PHP I can just call md5() to get an MD5 hash, but I had never actually tried MD5 in VB. I was worried that .NET might not have any MD5 support, in which case I would have to write it myself…. Orz. Luckily, when I checked MSDN, it turned out to be there. The process was a bit of a hassle, but fortunately MSDN provides a getMD5hash function, so I simply reused it. ...
MD5 isn’t really a program. It’s an encryption algorithm. The reason I say MD5 can prevent files from being modified is that it generates an MD5 code for a file. If the file has been changed (for example, by planting a Trojan), its MD5 code changes too. But generating this MD5 code isn’t something a person can do; it has to be done by a program. Today, I’m going to recommend a program called WindMD5. It can calculate a file’s MD5 code, so you can tell whether the file has been modified. After downloading a program, I suggest using WindMD5 to check whether the file has been modified. (Some websites provide the MD5 code for their files. Compare the MD5 code you generate with the one on the website, and you’ll know whether the file has been changed.) ...