Countering Spam Robots Computers Apart) are a form of HIP. CAPTCHAs are employed as means to prevent `bots' (that pose as human users) from indulging in spamming and other unscrupulous activities. The essence of a CAPTCHA is that it should be identified easily by a human but not by a bot. Broadly, CAPTCHAs can be classified into two groups: · · OCR (Optical Character Recognition) based Non-OCR based otherwise cannot interact with OCR-based and video/animated CAPTCHAs. CAPTCHAs have also been designed for deaf users (Shirali-Shahreza 2008). In Picture CAPTCHAs, picture(s) of some object(s) is/are shown to the user. The user has to identify the displayed objects or recognize some properties associated with these pictures. This mechanism exploits two facts: · · The human eye is naturally very good in recognizing pictures of objects. The large variety of objects present in the world makes recognition of pictures highly infeasible for a computer. OCR-based CAPTCHAs are mainly text-based CAPTCHAs in which the user is shown distorted images of letters and/or digits and the user is required to recognize them and type the answer. The OCR-based CAPTCHAs have been employed on many popular websites such as Google, Ya- hoo!, Hotmail, Facebook etc. However, these CAPTCHAs have an inherent limitation. Since In this chapter, we introduce two novel CAPTCHA schemes: Scrambled CAPTCHA and Hindi CAPTCHA. We also discuss their security implications and benefits. The following section discusses some broad associated definitions and