Esoteric Judaism or Crypto-Sumerianism is the secret knowledge held by top clerical elites of a number of denominations of Judaism, i.e. Haredi Orthodox Judaism, Mandaeism, denominations of core Median Judaism (and likely Shinto). Esoteric Judaism is the knowledge about the history, lineage and evolution of the ancient civilization of Judaism as it emerged in ancient Sumer and spread around the world.
Esoteric Judaism is a closely guarded secret and is passed down from generation to generation of top clerical leaders. The poskim (top rabbinic clerical leaders) revealed the secrets to rabbi Sabbatai Zevi (1626-1676) when they recognized him as the Mashiach, something which they later came to regret as a fateful mistake. Zevi passed down the secrets to others who later passed it down to Jacob Frank (1726-1791) who famously revealed the Crypto-Sumerian nature of Esoteric Judaism by reviving Sumerian ritual sex.
Esoteric Judaism is also about the nature of the Messianic era which is about the return to the Sumerian roots of Judaism, including to ritual sex, however this is not possible as long as there are sexually transmitted diseases (STD). Nevertheless, this is merely a scientific issue yet to be resolved by the emerging high tech revolution which is the true messianic age.
Knowledge about Esoteric Judaism can also be also be gleaned by studying the sacred scriptures of the Southern Jurisdiction of Judah, the Northern Jurisdiction of Israel and Mandaeism through the gates of learning of the Great Tradition of the Art of Writing.