Within Jewish mystical tradition, rearranging the Hebrew alphabet was never primarily about hiding a message from an enemy — it was a technique for finding meaning that scripture's surface reading did not reveal. Temurah, one of three classical methods of biblical interpretation alongside Gematria and Notarikon, treats the alphabet itself as something that can be folded, mirrored and recombined to expose a hidden layer beneath the text. Atbash is the most famous single technique in this family; it is one of several.
Atbash works by folding the 22-letter Hebrew alphabet exactly in half and pairing each letter with its mirror: Aleph (א, first) exchanges with Tav (ת, last), Bet (ב, second) with Shin (ש, second-to-last), and so on to the midpoint. The name is itself an Atbash-flavoured acronym: Aleph-Tav-Bet-Shin. Applied to the Latin alphabet, the same principle gives A↔Z, B↔Y, C↔X, continuing to the centre.
The clearest evidence of Atbash in an ancient text is in the Book of Jeremiah, where Sheshach (ששך) is the Atbash encoding of Babel (בבל), and Leb Kamai (לב קמי) encodes Kasdim — the Chaldeans. Scholars have long debated whether this was genuine concealment or a literary device meant to be recognised, since Atbash offers essentially no real security: it has no key, and once a reader knows the technique exists, the substitution is immediate.
The full pairing (Hebrew): א↔ת · ב↔ש · ג↔ר · ד↔ק · ה↔צ · ו↔פ · ז↔ע · ח↔ס · ט↔נ · י↔מ · כ↔ל. Eleven pairs cover all twenty-two letters with no letter left unpaired — a structural elegance that likely contributed to Atbash's endurance as the best-known Temurah method.
Atbash is the best known of three classical Temurah substitution methods, but not the only one. Albam and Achbi apply the same principle of folding the alphabet — they simply fold it differently.
Later Kabbalists extended Temurah well beyond these three named methods, generating dozens of permutation tables — but Atbash, Albam and Achbi remain the three considered foundational, and are the ones most consistently named together in surveys of the tradition.
Where Temurah rearranges letters, Gematria (גימטריה) reads them as numbers. Every Hebrew letter carries a fixed numeric value — Aleph is 1, Bet is 2, up through Yod at 10, then Kaf at 20, Lamed at 30, continuing by tens and then by hundreds to Tav at 400. Summing the values of a word's letters gives that word a number, and two words that share a sum are treated as meaningfully connected regardless of how different they look on the page.
The most famous single example is that chai (חי, "life") sums to 18 under the standard method — the reason 18 and its multiples are considered auspicious donation amounts in Jewish custom to this day. Gematria is not, strictly, a cipher for hiding communication; it is closer to a hermeneutic and numerological tool, included here because it shares Temurah's core premise that a text's surface form conceals a deeper, letter-level structure.
Notarikon works in the opposite direction from Gematria: instead of summing a word's letters, it treats each letter of a word as the initial of an entire new word or phrase, and reads the expanded sentence as the concealed meaning — or it takes the initial letters of an existing phrase and reads them as a new, condensed word. The name derives from the Latin notarius (shorthand scribe), reflecting its structural kinship with acrostic and abbreviation techniques used well beyond Jewish mysticism.
The clearest surviving example is אגלא (Agla), a name used in Kabbalistic and later ceremonial-magic amulets, formed as an acrostic of Atah Gibor Le'olam Adonai — "You are mighty forever, O Lord." Notarikon can run in either direction: expanding a short word into a phrase, or compressing a phrase into a memorable short form, and both directions appear throughout later Kabbalistic and Renaissance magical texts.
The most elaborate product of this letter-permutation tradition is the Shemhamphorasch — the 72-fold "Divided Name" or 72 Names of God, derived from three consecutive verses of Exodus (14:19, 14:20 and 14:21) describing the parting of the Red Sea. Each of these three verses contains exactly 72 letters in the Hebrew text. Read in sequence — verse one left to right, verse two right to left, verse three left to right again (a technique called boustrophedon, "as the ox ploughs") — the three verses can be divided into 72 three-letter names.
What this is used for — each of the 72 names is traditionally associated with an angel and, in later Kabbalistic and ceremonial magic practice (including its adoption into the Golden Dawn system), with a five-day span of the solar year, making the 72 Names function as a kind of extended zodiacal/angelic calendar layered on top of straightforward letter permutation.
These are hermeneutic and mystical tools first, ciphers second. Calling Atbash, Gematria or Notarikon "codes" in the modern cryptographic sense risks missing their actual historical function: they were ways of reading scripture more deeply, not ways of sending secure messages. Where concealment was the genuine goal — as scholars debate for the Jeremiah examples — it existed alongside, not instead of, the mystical reading practice.
Gematria's apparent numerical "coincidences" are a statistical certainty, not evidence of design. With 22 letters and short Hebrew words, many word pairs will inevitably share a Gematria sum by chance alone — a phenomenon parallel to the digit-sum pattern-matching seen in modern "angel numbers" content. This does not make the tradition meaningless; centuries of Kabbalists have found genuine interpretive value in the practice. It does mean a shared sum, on its own, is not proof of a hidden connection.