Sorry guys and girls, This time it is a tip for OpenBSD.
$ cksum -a sha512 /etc/passwd SHA512 (/etc/passwd) = b4d6a742cada5305686832f1037b60f79b56fe6dfdf9904e6070295e74 c2341535db26b731e27e04a73f0cb70bb589d31b8e9e18e207a8aae5aa81d06ea29f5a prints a very long checksum. This is also known as message digest or cryptographic hash in crypto parlance. In fact the RSA algorithm is based on this message digest algorithm but I don't think many people recognize this fact. RSA is basically an implementation of this concept a^b^c = a ^c^b = a^bc with modulo N thrown in. But the math will crumble down without relying on the cryptographic hash mechanism. Think of fingerprinting or signature. Now talking of signatures, PKI signatures also rely on message digests but that is a detail. IOW cksum(1) tells you whether a file has changed or not. For instance corrupted downloads and uploads can easily be detected by this utility. Here are the algorithms you can specify with the -a switch. cksum md4 md5 rmd160 sha1 sha256 sha384 sha512 sum sysvsum Of course you have sha1sum(1) and md5sum(1) in linux. You have cksum too but it does not seem to have these algorithms built into it. -Girish -- Gayatri Hitech web: http://gayatri-hitech.com SpamCheetah Spam filter: http://spam-cheetah.com _______________________________________________ To unsubscribe, email [email protected] with "unsubscribe <password> <address>" in the subject or body of the message. http://www.ae.iitm.ac.in/mailman/listinfo/ilugc
