12-06-2013, 04:51 PM
AUTHENTICATION
AUTHENTICATION.docx (Size: 21.65 KB / Downloads: 19)
Password Spaces
We distinguish that password systems have both theoretical and effective password spaces. The former space includes the set of all (theoretically) possible password. The vast majority of user choices tend to fall into a much smaller subset of the full theoretical password space, known as the effective password space
Overview of the Authentication Methods
Current authentication methods can be divided into three main areas:
• Token basedauthentication
• Biometric based authentication
• Knowledge based techniques
Token based techniques: This technique includes key cards, bank cards and smart cards are widely used. Many token-based authentication systems also use knowledge based techniques to enhance security. For example, ATM cards are generally used together with a PIN number.
Biometric based authentication: Techniques, such as fingerprints, iris scan, or facial recognition, are not yet widely adopted. The major drawback of this approach is that such systems can be expensive, and the identification process can be slow and often unreliable.
However, this type of technique provides the highest level of security.
Knowledge based techniques: are the most widely used authentication techniques and include both text-based and picture-based passwords. The picture-based techniques can be further divided into two categories: recognition- based and recall-based graphical techniques. Using recognition-based techniques, a user is presented with a set of images and the user passes the authentication by recognizing and identifying the images he or she selected during the registration stage. Using recall-based techniques, a user is asked to reproduce something that he or she created or selected earlier during the registration stage.