Shortly after it was ﬁrst introduced in 2006, diﬀerential privacy became the ﬂagship data privacy deﬁnition. Since then, numerous variants and extensions were proposed to adapt it to diﬀerent scenarios and attacker models. In this work, we propose a systematic taxonomy of these variants and extensions. We list all data privacy deﬁnitions based on diﬀerential privacy, and partition them into seven categories, depending on which aspect of the original deﬁnition is modiﬁed.
These categories act like dimensions: Variants from the same category cannot be combined, but variants from diﬀerent categories can be combined to form new deﬁnitions. We also establish a partial ordering of relative strength between these notions by summarizing existing results. Furthermore, we list which of these deﬁnitions satisfy some desirable properties, like composition, post-processing, and convexity by either providing a novel proof or collecting existing ones.