1. A method for measuring gesture-based password quality, the method comprising: receiving, using a hardware processor, a first image; receiving a proposed gesture-based password associated with the first image; identifying a plurality of points of interest in the received image, wherein the each of the plurality of points of interest is associated with at least one point of interest attribute; receiving a gesture selection function sequence, wherein the gesture selection function sequence comprises a plurality of gesture selection functions, wherein each gesture selection function is associated with a gesture type of a plurality of gesture types and at least one point of interest attribute, and wherein receiving the gesture selection function sequence comprises receiving a ranked list of gesture selection function sequences including a plurality of gesture selection function sequences ranked based on a probability that a user will use a password generated by the gesture selection function sequence as the proposed password; determining that a subset of the plurality of points of interest in the received image have point of interest attributes that correspond to attributes associated with the gesture selection functions of the gesture selection function sequence; generating a possible password for the first image based on the gesture selection functions in the gesture selection function sequence in response to determining that the subset of the plurality of points of interest correspond to the attributes associated with the gesture selection functions included in the particular gesture selection function sequence; determining whether the proposed password matches the possible password; determining a relative strength of the proposed password based at least in part on the determination of whether the proposed password matches the possible password; and causing the relative strength of the proposed password to be presented, wherein the proposed password includes at least three ordered gestures each of which is associated with a gesture type of the plurality of gesture types and at least one location in the first image, and wherein the proposed password includes at least three ordered gestures each of which is associated with a gesture type of the plurality of gesture types and at least one location in the first image.