Bischoff Summary

A list of mediaeval cipher manuscripts

This list is extracted from Bernhard Bischoff, >i>Ubersicht uber die nichtdiplomatischen Geheimschriften des Mittelalters (Sonderdruck aus Mitteilungen des Instituts fur Osterreichische Geschichtsforschung Band LXII), Graz 1954.

Bernhard Bischoff (1906-1991) was an internationally renowned palaeographer and had an encyclopaedic knowledge of his subject. This monograph of 27 pages summarises examples of non-diplomatic mediaeval cipher writing known to him. It is clear that he did not know of any cipher system of the period which was not essentially a simple substitution cipher. Almost all of the manuscripts cited contain a few words and phrases of ciphertext inserted into normal manuscripts: he gives only one example of a manuscript written entirely in cipher.

Manuscript Content Provenance Date
Normal letters
Plaintext letters retained
Text written in vertical columns
Paris BN Lat 1868 f1r Jerome, Epistles s. 9
Frauenfeld Cod Y 38 a f 5v
Reversal of sentences
Milan Ambros A inf 220 f. 56 Josephus s 9
Reversal of words
Oxford St John’s Coll. 1736 (Thorney 1109/10) f 5v
clm 14640 f 68r 1445
Reversal of syllables
Mirror writing
Oxford Bodl Auct T II 28 (20629) f. 42v Solin, Fleury s. 9/10
Heiligenkreuz 250 f 168r s 12
Liege Univ Bibl 26c f 1 s 12
Regular transposition of neighbouring letters
Paris BN Lat 2196 f 68r-69r Cassiodorus In Psalmos s 9
clm 14614 f 78r s 9
Eton Coll L 6.5 s 11
St Gall 270 p 52 s 9
Insertion of null letters
Wolfenbuttel 727 Helmst. f 153 s. 14/15
Omission of letters
Vatic Regin lat 314 f 117rv s9
Of vowels
By the following consonant

By the preceding consonant
Florence Bibl Naz, Conv Soppr I II 44 f 51r The Cathar work Liber de duobus principiis s. 13
By some other consonant
By the following vowel
Oxford St John’s Coll. 1736 (1109/10) f 5v s 11
By a neighbouring consonant
Formerly Cheltenham 816 f 32r s 11
Vatic Palat lat 216 f 70v s 8/9
Reciprocal transposition
Paris BN Lat 229 s 12
A Wolfenbuttel manuscript of 1433
Vienna 1674 f 3v
Replacement of each letter by the following letter
Vatic Palat lat 485 f 14v Lorsch s 9
Laon 444 f 310v Martin of Laon s 9
Oxford St John’s Coll. 17 f 5v 1109/10
St Gall 186 p 193 s 9
Rome Bibl Naz 278 (Farfa 27) f 3v s 11/12
Replacement of each letter by the preceding
Paris BN Allem 238 s 16 f 1-3 s 16
Replacement of abc by zxy (atbash)
clm 19550 f 244 A recipe s 15
Substitution of letters by other keys
clm 14367 f 226v s 14
London BM Sloane 1754 f 63r\n65r\n75r Roger Bacon Tractatus Trium Verborum s 14
(The genuine Roger Bacon cipher discussed by Newbold and solved by Manly).
Karlsruhe 399 f 229 s 15
Substitution by letters and numerals
London BM Sloane 416 f 15r Recipes and instructions on pigments. English, Italian and Latin s 15
Substitution by letters and symbols
Vatic Lat 3102 f 27rv Quaestiones Bernardi (an alchemical treatise) s.14
Newbold plates XXVII and XXVIII. Solved by Manly.
Substitution by letters and deceptive symbols
London BM Sloane 351 f 15v s 15
London Lambeth Palace 477 f 120v\n142v s 15
Use of foreign alphabets
Covered by Bischoff in another paper, Byz. Zs 44 1951 34 ff.

Square character, left to right
clm 641 f 40r-42v Compendium by Hermann Schedel s. 15
BM Royal 12 E VII f 221r Recipes s. 12/13
clm 4594 f 29v s 15
Rabbinical characters, left to right
clm 15613 f 230v s 15
clm 18662 f 241v
Wiesbaden 35 f 137v s 15
Manufactured alphabets

Mixed Greek and Hebrew letters
Karlsruhe Karlsr. 340 s 9
Vienna 2223 f 20r\n20v\n21r\n56r\n72r s9
Paris BN Lat 12048 f 264r s 8
clm 6411 f1r Not deciphered s. 9
London BM Royal 12 E VIII f 221 Superstitious recipe s 12/13
Bern 207 f4r Fleury s8
Uber Valenciennes 59 f 2r Fleury (?) 806
Douai 12 c. 800
Arras 1045 f 15r s 9
clm 13067 f17v s11
Prag NUB Lobk 491 f 61r Recipes s 15 key s16
Bern 207 f 3r
Oxford St John’s College 17 f 7v
The alphabet of Aethicus Hister
Bern 207 f 2v

Avranches 152 (107) s 11
Oxford St John’s College 17 f 5v
Vatic Rigin lat 294 f 1v s 11/12
Valenciennes 59 f 28r
Bern 85 f 117r Breton evangeliary s 9
Oxford St. John’s College 194 f 65r Gospels s 9
Paris BN lat 974 f 25v Augustine s 9
clm 276 f 96v s14
clm 14684 f 100v s 15
clm 14684 f 100v s15
Vienna 2674 f 5r Notizbuch of Frederick II
Invented alphabets
Wolfenbuttel Weiss 14 f 40v s 9
clm 14370 f 42 s10
clm 642 f 42r Encyclopaedia Pruhl s 11
clm 6242 f 165r Freising
Ghent 257 f 1r Trier s 10/11
London BM Add 34248 s11
clm 18628 f 95r Superstitious recipes Tegernsee

s 10
clm 14386 f 5r marg\nf 88v St Emmeram s10/11
clm 18628 f 95r
D1, D2
clm 6396 f 99r Freising s 10
clm 18547 b f 185v Tegernsee s 11
La Cava 3 f 255v s 11
Vienna 1134 Lectionary Villiers, Brabant s 12
Cologne Histor Arch W schm. f 149 Astrology 1480
Prague Metrop.-Bibl M CXXV f 1 s 15
Karlsruhe Aug 152 f 45v s 15
Predominantly invented alphabets
Vienna Cod 751 Boniface, Letters s. 9
Leiden Voss. lat oct 41 65v s 9
Leiden Voss. lat qu. 63 f 3r Gregory of Tours Tours s. 8
Cologne Dombibliothek 43 f 56v Job, Tobit Italian s 8
Paris B.N. Nouv. Acq. Lat. 1489 f 1r s9
Stuttgart Zwif 253 The lingua ignota of Hildegard of Bingen s. 12
Only this manuscript of the lingua ignota is written in a secret script.
F The secret writing of Duke Rudolph IV of Austria
Klosterneuburg 1226 s. 15
clm 671 f 109r s. 15
Munich Univ Bibl 4o 810 f 41v\n56r s. 15
Formerly Vienna Gilhofer and Ranschburg Catal 265 nr 7 f 22r s. 15
clm 641 f 38r s. 15
clm 3131 f 170r s. 15
Melk 931 (1086) p 55 s. 15
clm 405 f 175 Recipes s14
Leipzig Univ-bibl 1048 f 278v 1444
Prague Metrop. A LIX 6 (94) f 48v
clm 24104 f 79v Johannes Regiomontanus 1487
clm 444 f 140r Cosmetic recipes s. 15
clm 276 f 96v s 14
clm 641 f 38r s. 15
clm 716 f 62v Hartmann Schedel Liber antiquitatum s. 15
Paris BN Nouv Acq Lat 635 Secretum de thesauro experimentorum jmaginationis hominum Italian s 15
The entire manuscript is in cipher apart from the contents, title and concluding formula. Described in H. Omont Bibl de l’Ec. d,
58 (1897) 253-258
Formerly Vienna Gilhofer and Raschburg Catal 265 nr 7
clm 570 f 42v s 15
Prague Metrop-Bibl O LXXVIIII (1662) f 295v s 15
Heidelberg Pal. germ. 597 Alchymey teuczsch s 15
clm 641 f 38r s 15
clm 644 f 51v-52r s 15
Gottingen, Morbio 15 Astronomical observations Italian s 14
Vatic Borghes 239 f 16r
Symbols mixed with Arabic numerals

Naples Bibliotheca Nazionale MS XII A 23 (formerly 334. VI. 9. 36) title page Mare Vitreum, a canonistic compendium s 12
Madrid Bibl Nac 10007 (formerly Tol. 10, 25) f 207r West Gothic 902
Cambridge, Peterhouse 75 f 14r\n30v\n63v Astronomica s 14
Prague Metrop.-Bibl. M XVII (1370) f 1rv\n4r\n9rvN10r Chemical recipes s. 14
Paris Arsenal 940 f 38v Passio Mauritii et Sociorum s. 15
Frankfurt a.M. Barth. 91 f 184r etc s 15
Wolfenbuttel 55 7 Aug 4o Alchemical s. 15
Prague Metrop.-Bibl. M CXXV f 1 s15
clm 14698 f 307r s15
Spanish neums mixed with letters
Frankish neums, symbols and letters
clm 18628 f 95 Tegernsee s 10
Vienna 1761 f 105 s 10/11
Augsburg Ordinariatsbibl 6 f 88v 98r 90 r Gospels s 9
clm 3860 a f 7v Canons Augsburg s 9/10
Numerical ciphers and related
Vowels replaced with numerals
Replacement with abbreviated ordinal numerals (pri, sec, ter…)
clm 1086 f 71v Hugeburc Vitae SS Wynnebaldi et Willibaldi s. 8-9
Replacement with the sequence x, xx, xxx, xl…
Cordova, Albarus Codex
Replacement with Arabic numerals
A: 1 2 3 4 5
Vienna 2674 f 7r Frederick III
clm 671 f 61 57r s 15
B: 5 4 3 2 1
clm 674 f 27v s 15
C: 5 6 7 8 9
Bamberg Canon. 26 f 305v s 14
D: 1 2 0 4 X
Florence Bibl Naz, Conv Soppr I II 44 f 51r Liber de duobus principiis (a Cathar work) s. 13
Substitution of dots (variations on . : :.)
Paris B N Bat 229 s 12
clm 14848 f 144v A nun’s prayerbook s. 12
Berlin Lat fol 88 f 59v Recipes s. 14/15
clm 13099 f 187v s. 12/13
Schlagl 454 a 61 f 50v
Substitution of G GG GGG…
Oxford St. John’s College 17 f 5v
Substitution of vertical or diagonal lines
A diagonal, similar to ogham
clm 4115 f 42r Leges s. 8/9
B vertical lines
Vienna 2674 f 7r Frederick III
Substitution of p with one to five underlinings
London BM Harl. 2277
Lubeck Stadtbibl Ms theol 76 f 89r s. 15
clm 14412 f 48v s 15
Rouen 1151 1471
Corpus Christi Cambridge 96 f 240r Not deciphered c 1425
Replacement of the entire alphabet with numerals and the like
Replacement of the letters with their positional number
A Roman numerals
Laon 444 f 310 Martin of Laon s 9
Vatic Palat lat 485 f 14v Lorsch s. 9
Vatic Rigin lat 421 f 26r s 11
Vienna 1761 f 105v s 10/11
Paris BN Lat 7503 f 92v St Gall s. 9
Vienna 795 f 20r s 9
Oxford St John’s Coll. 17 f 5v 1109/10
Arabic Numerals
Vienna 2674 f 7r Frederick III
Clofruna, clophruna
Paris BN Nouv Acq Lat 1443 f 190v Augustine Letters s. 9
St Gall 176
Iisruna, lagoruna, hahalruna, stofruna
Vienna 911 f 21r s 9
A possible runic alphabet
Vatic Regin lat 421 f 26r s 11
Vienna 1761 f 105r s 10/11
Greek numerals representing alphabetical position
Discussed by Bischoff elsewhere: he notes that Trithemius revived this system.
‘Chaldaic’ or ‘Greek’ numeral representing alphabetical position
Heidelberg Pal germ 368 f 65r\n68r Superstitious recipes s. 15
Replacement by ‘Chaldaic’ or ‘Greek’ numerals in grammatical order (i.e. vowels, liquids, plosives)
London BM Sloane 351 f 14v s. 15
Other numerical keys
clm 16226 f 275v s. 15
Pigpen cipher
Gottingen Luneb 2 f 101r s 15
clm 16226 f 275r s 15
clm 16488 f 43v s 15
Paris BN Allem 238 f 1 s 16
Musical notes
London BM Sloane 351 f 15r s 15