A method of text-based authentication that accounts for positional variability of biometric features between captured biometric data samples includes capturing biometric data for a desired biometric type from an individual, and processing the captured biometric data to generate a biometric image and a biometric feature template. A selected conversion algorithm is executed by superimposing a positional relationship medium on the biometric image. The positional relationship medium includes a plurality of cells textually describable with words derivable from the positional relationship medium. The positions of biometric features are permitted to vary in overlapping border regions within the positional relationship medium. The method also includes identifying the position of at least one biometric feature within the overlapping border regions and generating a plurality of words for the at least one biometric feature.