monline

HashTab makes it easy (using context menu items in Mac's Finder and Windows' Explorer) to generate all kinds of checksums of a selected file (unfortunately it does not support multiple file selections). In v1.2 of the Mac port the following hash functions are available: CRC32, HAVAL (32-3, 32-4, 32-5), MD2, MD4, MD5, RIPEMD (128, 160, 256, 320), SHA (1, 224, 385, 512), Tiger, Whirlpool. My personal favourite is Whirlpool, but for file integrity checking MD5 became the defacto standard, ie. this is the one you'll most likely encounter on download pages.

As a developer/admin, sometimes you might have to generate the MD5 hash of a string. Eg. last time I had to do this, when I installed the admin interface of XCache on a server. I had to create an MD5 of the admin password and put it into xcache.ini. The docs said that I should create a PHP file with something like <?php echo md5('the_password'); ?> to get the MD5 hash. However there's a much faster way, a simple command line.

I'm going to add (or at least design) digital signature support for my company's application framework and I read through the Wikipedia article on digital signatures to freshen up things a little bit. The last paragraphs talk about use of smart cards with dig. signatures. They say that smart cards are one of the most widely used methods for securing private keys for everyday use. This made me think a little bit.

I've just gone through the Java Cryptography Extension 1.2.2 API Specification & Reference document to read some examples on use of JCE. I want to use RSA encryption and in Java JCE is the way to go. However the JCE examples in the above doc do not even mention RSA! They tell about DES, DESede (Triple DES), Blowfish, but no word on RSA. This is quite strange, isn't it?