1. A method in a biometric sensing system comprising a two-dimensional biometric sensor of authenticating a user using a body part including biometric information, the method comprising: stitching partial enrolment images comprising different views of the user's body part into one or more mosaics and thereby creating a single enrolled image, wherein each partial enrolment image corresponds to a single and separate touch of the body part on the two-dimensional biometric sensor, acquiring an authentication image of the body part, wherein: (i) the authentication image corresponds to a single touch of the body part on the two-dimensional biometric sensor and has an area, and (ii) a size of the authentication image is a fraction of the enrolled image, determining at least one area of interest in the enrolled image that corresponds to the authentication image by comparing features in the authentication image with features in the enrolled image, wherein a difference in size between the at least one area of interest and the area of the authentication image is below a tolerance value, and matching the authentication image with the enrolled image by using a matching algorithm to compare the authentication image with image data of the determined at least one area of interest in the enrolled image, and thereby enabling authentication of the user.