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Probably, you don’t think too much about your hard drive, but what would you do without all those precious files that you keep in your disk?

Photos, musics, financial records, or your PHD paper that you’ve been working for years.

When was the last time you backup your files? Backups can save your data and even (why not?) your life. If you are a heavy user or you cannot stay without your computer for a few hours, a backup is vital.

But, how many times do you need backup your files?

Well, you have to think that the idea behind a backup is keep your important files safe from a disaster. So, you could backup once a week, once a day or once a year. Everything depends on how important your files are for you.

Ok, now you agree that backup is a serious thing, but where? Your hard drive is huge and you don’t know where you can keep your copies.
An USB drive? Or a CD-R/W? A FTP server? Or a network drive?

Maybe all of them? Backup Platinum makes a reserve copy of your critical data virtually to any type of storage media: hard or USB drives, CD-R/W or DVD±R/RW media, FTP server or Local Area Network. The program helps you to define the backup set: what, where, how and when to backup. It’s 128-bit encrypted with Blowfish, uses ZIP compression to keep your backups small and secure and automatically split large backups to several parts using disk spanning. It’s a great tool.

Now it’s your turn. A serious backup routine could make all the difference for you.

It’s quite difficult to write a book in cryptography today and not talk about RSA, DSA, keys and the internet. Some make the effort to write about a bit of history, information theory and the arcane cryptosystems, but so far I’ve only found small references just for the sake of having it.

If you don’t understand the basics, the advanced may sound right, but faint. If you don’t have a hands-on experience with the basic technics, you’ll never get quite right the more advanced stuff, that’s why I strongly recommend this book. It was written in the sixties with the intent to describe basic cryptanalysis that was already obsolete at that time, specially after the WWII when cryptanalysis was boosted to a new level.

The book always explain the concepts by examples. Every chapter have a encrypted text that needs decryption and then the author goes on through the theory and practice of solving it. As the theory is worked out together with the practice you won’t loose any important concept, what always happens in mathematical texts (minimal theory, one useless example and lots of exercises).

It’s organized in five parts, one for each basic cryptosystem: direct standard alphabet (caesar cipher, rot13), generic monoalphabetic substitution (linear transformations), polyalphabetic substitution, polygraphic systems (matrices) and transpositions. All of which are, somehow still used in advanced cryptography, so the knowledge of how it used to work in plain text will definitely give you important clues on how to understand even the Rijndael (a.k.a. AES) algorithm.

I’m also building a tool kit to help me checkpoint my work throughout the book.

You can find the book at Amazon UK following clicking in the picture:

For Amazon US and International, follow this link: Elementary Cryptanalysis: A Mathematical Approach