Scene of the Cybercrime: Computer Forensics Handbook
An introduction to the field of law enforcement for IT professionals.
TABLE OF CONTENTS Scene of the Cybercrime: Computer Forensics Handbook
Understanding Basic Cryptography Concepts
Cryptography is a word derived from the Greek kryptos ( hidden ), and the use of cryptography pre-dates the computer age by hundreds of years. Keeping secrets has long been a concern of human beings, and the purpose of cryptography is to hide information or change it so that it is incomprehensible to people for whom it is not intended. Cryptographic techniques include:
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Encryption, which involves applying a procedure called an algorithm to plain text to turn it into something that will appear to be gibberish to anyone who doesn t have the key to decrypt it.
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Steganography, which is a means of hiding the existence of the data, not just its contents. This is usually done by concealing it within other, innocuous data.
| Note | The words cryptography and encryption are often used interchangeably, but cryptography is a much broader term than encryption; encryption is a form of cryptography. In other words, all encryption is cryptography, but not all cryptography is encryption. |
Understanding the Purposes of Cryptographic Security
Cryptographic techniques are an important part of a multilayered security plan. Some security measures, such as implementation of a firewall and use of access permissions, attempt to keep intruders out of the network or computer altogether, much like fences and door locks attempt to keep burglars off the grounds or out of the house. Cryptography provides an inner line of defense. Like a wall safe that is there in case the burglars do make it inside your house and...
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