At a glanceKey from external plaintext · complete
- The letter
- Philip IV to Cardinal Gil de Albornoz, his ambassador to the Pope, Madrid, 24 July 1648, countersigned by the secretary Pedro Coloma. Two copies of the same letter, the body in cipher, the opening and closing formulas in clear; no decipherment was filed with them.
- Where
- Archivo Histórico de la Nobleza (Toledo), Osuna papers, OSUNA,CT.2,D.32(1-2): copy A on images 2–3, copy B on image 5 (PARES 3939398). Catalogue no. 747 here, which lists 69 shelfmarks of Albornoz’s embassy papers; four are digitised.
- The cipher
- A syllabic cipher. A syllable is written as another syllable with the consonant changed and the vowel kept (mo = co, ne = de, ra = sa), numbers in series of five give more syllables (45–49 = ra re ri ro ru), and a few signs stand for words (a cross for que, sal for Su Santidad).
- How the key was found
- Brice Dudout found the same cipher in a chapter of a letter of Luis de Haro, 25 September 1649, enciphered for Albornoz, whose plain copy was kept (OSUNA,CT.11,D.1). He built the key on its first twelve lines, froze it and tested it on the other eleven: 0.859 of their letters, against 0.476 at the 99th percentile of keys with shuffled values. The royal cipher of 1644–45, rebuilt from two other letters of the fonds, does not fit this letter.
- What it says
- The King insists that Albornoz obtain from Innocent X that the nuncio at Madrid, Giulio Rospigliosi, Archbishop of Tarsus and later Pope Clement IX, keep his post: “no puede haver instrumento más a propósito”, and the ambassador is not to give up “por ningún caso”.
- Still open
- Six of 359 groups: four code signs found only in this letter (74, an underlined A, 124 twice, a cross with 11) and one group before respondió. About five more are probable readings.
- Credit
- Brice Dudout (Europe chiffrée), working with Claude Opus 5.5: the inventory of no. 747, both keys and their held-out tests, the transcription of both copies, the Spanish text and the English translation. His write-up. The plain copies made at the time and filed with the 1649 chapter and the 1644–45 letters supplied the keys.
01 The letter
In 1648 Innocent X was renewing his nuncios. Philip IV wanted to keep his own at Madrid: Giulio Rospigliosi (1600–1669), titular Archbishop of Tarsus, nuncio in Spain since 1644. A royal letter of 10 January 1648 (OSUNA,C.1983,D.7, not digitised) had asked Cardinal Gil de Albornoz, the King’s ambassador to the Pope, to obtain that “the Archbishop of Tarsus, nuncio of Spain, continue his residence”. Albornoz answered on 24 March with what the Pope had said. This letter of 24 July is the King’s reply: the opening that acknowledges the March letter is in clear, the body in cipher, and the closing formulas, the date, Yo el Rey and the countersignature of Pedro Coloma are in clear again.
The letter survives twice in the Osuna papers of the Archivo Histórico de la Nobleza: copy A on images 2–3 of the PARES record, copy B on image 5, the original and the duplicate, both in the same chancery hand. Copy A repeats half a line and cancels it with 4s written above it; copy B cancels one group inside sujeto. Otherwise the two copies agree group for group, apart from a few copying slips. No decipherment, interlinear or separate, was filed with either.
The Albornoz embassy papers passed, with the cardinal’s successor in Rome, into the archive of the Dukes of the Infantado and then into that of the Dukes of Osuna. Catalogue no. 747 here lists 69 of their shelfmarks with cipher; only four are digitised on PARES, and the other three hold the plain copies from which the keys were rebuilt and tested.
02 The cipher
The cipher is built on syllables. Most of the groups look like Spanish syllables or small numbers, and almost none of them means what it looks like:
| kind | how it works | examples |
|---|---|---|
| syllables | consonant changed, vowel kept | mo = co, ne = de, ri = si, la = pa, ti = mi, ro = so, so = ta, de = ve, ru = su |
| vowel + consonant | n written r, l written t | er = en, or = on, ar = an, et = el; also el = es, il = is, al = as |
| numbers | series of five, one per vowel | 25–29 fa fe fi fo fu, 30–34 ga…gu, 35–39 la le li lo lu, 40–44 ña ne ni no nu, 45–49 ra…ru, 50–54 ta te ti to tu |
| single letters | letters and small numbers | 2 = n, e = n, n = s, m = r, r = a, 23 = o, 6 = t, 12 = d, 18 = l, x = e, g = y (also p), 4 = s or a comma |
| words | signs | a cross ✗ = que, sal = Su Santidad; in the 1649 chapter also gus = guerra, ile = Armada |
From Brice Dudout’s key K2 and its additions (targets/albornoz1648/key_K2.tsv, key_K2b_additions.tsv).
So ne ri 4 so il is de si s ta is, “desistáis”, and lo m 42 e 34 e ma ro is po r ni n gu n ca so, “por ningún caso”. The royal letters of 1644–45 in the same fonds use a cipher of the same kind with other values: numbered syllables in series of five (30–34 = ma me mi mo mu), letters for letters (a = c, c = n, f = r) and syllables written vowel first (ac = la, ap = sa). The 1648 letter is not in it.
03 How the key was found
The digitised pieces. Of the 69 shelfmarks of no. 747, four have images on PARES: CT.2,D.16 (Philip IV to Albornoz, 12 December 1644), CT.2,D.20 (26 January 1645), CT.2,D.32 (this letter) and CT.11,D.1 (1649). Brice Dudout wrote a protocol before computing anything: each key built on one text, frozen with a SHA-256 hash, and tested on text kept out of the work.
A key that does not fit. D.16 keeps its cipher original (images 2–4) and a plain copy made at the time (images 6–8). Aligning them gave K1, the royal cipher of 1644–45, which was frozen and tested on D.20, transcribed before its plain copy was opened: K1 recovered 0.638 of D.20’s letters, against a median of 0.467 and a 99th percentile of 0.550 for 200 control keys with the values permuted. Applied to the 1648 letter, K1 gives nothing: the letter is made of syllable groups (ne, mo, ma, so, ri) and numbers from 2 to 61 that K1 does not have.
The key from the 1649 chapter. CT.11,D.1 holds a chapter of a letter of Luis de Haro to the Count of Peñaranda, Madrid, 25 September 1649, on the army of Catalonia, enciphered “to send to Cardinal Albornoz” (image 3), with its plain copy (image 1). It is in the cipher of the 1648 letter. The words dentro de Cataluña y, enciphered twice in the same way, 2 ℓ48 ne ma so 39 40 g, opened the alignment. The key K2 was learnt on lines 1–12 only and frozen. Lines 13–23, decoded mechanically with the frozen key, recover 0.859 of the letters of the plain copy, against a median of 0.419 and a 99th percentile of 0.476 for 200 control keys with the values permuted. The protocol had named a word-level score; the test used a letter-level one (the longest common subsequence of normalised letters), because a mechanical syllabic decoding does not divide words reliably. Both tests clear their controls by a wide margin.
The letter. Both copies of the 1648 letter were transcribed and decoded with K2. K2 left some single letters and series numbers without a value; 29 values were added on the letter (K2b), each attested at least twice, fitting its series of five, or confirmed by the other copy: e = n, r = a, 23 = o, the cross = que, 25 = fa, 54 = tu. Copy B, the cleaner, was then checked group by group against copy A, and copy A was followed where B departs from the key.
The statistical check here. The project’s validator (docs/_validate.py) scores the reading of 636 groups (84 types) with a four-gram model of Golden Age Spanish, as mean log-probability per letter. The reading scores −2.038; random keys of the same shape −3.743 on average; a key annealed onto the shuffled ciphertext −2.535 at best; and the same annealer, started from random keys on the real text, reaches −2.246. Verdict: pass.
04 The decipherment
Brice Dudout’s text: spelling of the letter kept, punctuation and accents added. {x} probable reading; ‹…› unresolved group; [x] restored from the sense. The opening and the closing, in clear in the letter, are left out.
[…] so{b}re la continuación del arçobispo de Tarso, aunque se provean las otras nunciaturas. Ve{o} ‹74› [que] pasastis los oficios con Su Santidad, y lo que ‹el› respondió mostrando los ‹A›s que en ‹124› considera;
[…] about the continuance of the Archbishop of Tarsus, even if the other nunciatures are filled. I see ‹…› [that] you made representations to His Holiness, and what he answered, showing the ‹…› that he considers in ‹…›;
pero todavía, siendo este sujeto muy digno de favor por la atención con que acude a su ministerio y a la representación en que está, y que para las conveniencias del servicio [de] su príncipe y mío no puede haver instrumento más a propósito, buelvo a encargaros continuéis y esforcéis con Su {Be}atitud las instancias para su detención ‹✗11› en conformidad de las primeras órdenes, y que no desistáis por ningún caso, como en negocio que incluye en sí conveniencias del servicio de Su Santidad y mío;
but nevertheless, this person being most worthy of favour for the care with which he attends to his ministry and to the representation he holds, and since for the interests of the service of his prince and mine there can be no instrument more suitable, I again charge you to continue and redouble with His Beatitude the requests for his retention ‹…›, in accordance with the first orders, and not to desist in any case, as in a business that contains interests of the service of His Holiness and mine;
y daréisme quenta de lo que resultare y se fuere ofreciendo en ‹124›.
and you will report to me what results and whatever may arise in ‹…›.
“His prince and mine”: the nuncio served two masters, the Pope whom he represented and the King at whose court he lived, and the King argues that keeping him serves both. Rospigliosi did stay at Madrid until 1653. He later became Cardinal Secretary of State and, in 1667, Pope Clement IX. Albornoz was given leave to return to Spain in 1649 and died in December of that year.
05 What remains uncertain
Copy B has 359 cipher groups. 353 have a value (98.3%), about five of them probable readings; six are unresolved. By the project’s grades, the values of K2 rest on a known-plaintext letter (C), the K2b additions and the probable readings are M, and the two words restored from the sense are I.
- 74, in “Ve{o} ‹74› pasastis”: a code sign, probably que.
- An underlined A, in “mostrando los ‹A›s”: a code sign for a plural noun, perhaps inconvenientes.
- 124, twice: “que en ‹124› considera” and “se fuere ofreciendo en ‹124›”.
- A cross with 11, ✗11, in “su detención ‹✗11› en conformidad”.
- The group before respondió: copy B has el (es), copy A ol (os); the sense wants él.
- Probable readings: the b of sobre is written with the sign for a; the “Be” of Beatitud with the syllable vo; the o of Veo.
The four code signs occur only here, and the 1649 chapter does not use them. Another letter in the same cipher would settle them; none of the other digitised pieces of no. 747 is in it, and the remaining 65 shelfmarks have no images.
No earlier decipherment was found. The PARES record gives only the subject (“para que continúe en sus funciones el Nuncio”); X. Arriazu García’s thesis on Albornoz’s mission (Barcelona, 2024) cites other cipher letters of the Osuna fonds, not this one; a web search on 27–28 October 2026 found nothing.
Full texts
The transcription and the decryption of every document on this page, so that the reading can be used and checked. Short files are shown here; all are in the repository.
Philip IV to Cardinal Albornoz, Madrid, 24 July 1648 (AHNOB OSUNA,CT.2,D.32)
In 1648 Innocent X was renewing his nuncios. Philip IV wanted to keep his own: Giulio Rospigliosi, Archbishop of Tarsus, nuncio at Madrid since 1644 – the future Pope Clement IX. He wrote so to his ambassador to the Pope, Cardinal Gil de Albornoz, in a cipher nobody had read: “there can be no instrument more suitable” for the service of both courts, so the ambassador must not desist “in any case”. The letter survives in two ciphered copies with no decipherment; the key came from another paper in the same family archive, a chapter of a letter by Luis de Haro enciphered for Albornoz in 1649, whose plain-text copy was kept.
Transcription
# AHNOB, OSUNA,CT.2,D.32(1-2): Philip IV to Cardinal Albornoz, Madrid, 24 July 1648. Two cipher copies of the same letter.
# Tokens separated by spaces, one manuscript line per row. ✗ = cross sign (code, = que); A̲ = underlined A; ✗11 = cross with 11.
# The opening ("En carta de 24 de março ... de 10 de enero") and the closing formulas are in plain text and are not transcribed.
## Copy B (image 5): reference copy
B01 4 ro r 46 35 mo e 52 44 r mi or ne 18 r m mo di 4 lo ne
B02 so m ro r ur ✗ re g 48 de ar 35 n 23 6 45 n 44 e mi r 54 45
B03 n 4 de 23 74 la ra 4 52 n 38 n 23 27 mi ol mo e sal g 38
B04 ✗ el m el lo e ni 23 to n 6 45 e no 38 n A̲ n ✗ er 124 mo e ri
B05 ne 45 le 48 53 na di r ri er no el 51 ru 31 33 53 tu g ni 15 43 ne
B06 25 do s lo m 35 r 51 e mi or mo e ✗ r mu ne r ru ti 42 n
B07 51 47 23 g r 35 m x g 46 re e so mi or er ✗ el so g ✗
B08 la 45 35 n mo d de 42 er mi al ne 18 re m di mi 23
B09 ru g 47 e mi le g ti 23 43 lu x ne a r de s ir n 6 49
B10 te 2 53 ta 4 r g 48 lo ri 53 du et do r er ma s 30 48 n mo
B11 e 52 44 x il g el 28 m me il mo e ru do r 52 54 12 35 n ir
B12 n 50 2 mi al la 45 ru ne 51 e mi or r ✗11 er mo e 28 m ti na 12 ne 35
B13 n g 47 te 45 n 23 m ne 41 n g ✗ 43 ne ri 4 so il lo m 42 e 34 e ma ro mo
B14 to er 41 33 mi 23 ✗ ir t 39 pe er ri mo d de 42 er mi al ne 18 re m di mi f
B15 ne ru ne e 52 na 12 g ti 23 g g na 46 il te ✗ e 50 ne 38 ✗ 46 ru 18 50 46 g re
B16 29 x 46 23 y 46 mi er no er 124 4
## Copy A (images 2-3): checked group by group against B; cancelled repetitions given as comments.
# Copy A is transcribed as far as "de Su Santidad y mío y" (B15); the last stretch ("daréisme quenta ... en 124") is read from B.
A01 4 ro r 46 35 mo e 52 44 r mi or ne 18 r m mo di 4 lo
A02 ne so m ro r ur ✗ re g 48 de ar 35 n 23 6 45 n 44 e mi r
A03 54 45 n 4 de 23 74 la ra 4 52 n 38 n 23 27 mi ol mo e
A04 sal g 38 ✗ ol m el lo e ni 23 to n 6 45 e no 38 n A̲ n ✗
A05 er 124 mo e ri ne 45 le 48 53 na di r ri or no el 51 m 31 53
A06 tu g ni 15 43 ne 25 do s lo m 35 r 51 e mi or mo e ✗ r mu
A07 ne r m ti 42 n 51 47 23 g r 35 m x g 46 re e so mi or
# (cancelled line: e ✗ r mu ne r m ti 42 n 51 47 23), then:
A08 er ✗ el so g ✗
A09 45 35 n mo d de 42 er mi al ne 18 re m di mi
A10 ne m g 47 e mi le g ti 23 43 lu x ne a r de s
A11 ir n 6 49 te 2 53 ta 4 r g 48 lo ri 53 du et do
A12 r er ma s 30 48 n mo e 52 44 x il g el 28 m me
A13 il mo e m de r 52 54 12 35 n ir n 50 2 mi al
A14 la 45 m ne 51 e mi or r ✗11 er mo e 28 m ti na 12
A15 ne 35 n g 47 te 45 n 23 m ne 41 n g ✗ 43
# (cancelled: ri 4 so / tl, marked with "4"s above)
A16 ne ri 4 so il lo m 42 e 34 e ma ro mo to er 41
A17 33 mi 23 ✗ ir t 39 pe er ri mo d de 42 er mi al
A18 ne 18 re m di mi f ne m ra e 52 na 12 g ti 23 gDecryption
# Decryption of OSUNA,CT.2,D.32, line by line, with key K2 + K2b (key_K2.tsv, key_K2b_additions.tsv).
# For each line: the tokens; the value of each token in turn (‹x› = token without a value); for copy B, the established
# text of that line ({x} probable, ‹x› unresolved, [x] restored from the sense, *x* plain text in the original).
## Copy B (image 5)
B01 4 ro r 46 35 mo e 52 44 r mi or ne 18 r m mo di 4 lo ne
s so a re la co n ti nu a ci on de l a r co vi s po de
= *En carta de 24 de março avisáis el recibo de la que se os escrivió en 10 de enero* so{b}re la continuación del arçobispo de
B02 so m ro r ur ✗ re g 48 de ar 35 n 23 6 45 n 44 e mi r 54 45
ta r so a un que se y ro ve an la s o t ra s nu n ci a tu ra
= Tarso, aunque se provean las otras nunciatura
B03 n 4 de 23 74 la ra 4 52 n 38 n 23 27 mi ol mo e sal g 38
s s ve o ‹74› pa sa s ti s lo s o fi ci os co n [Su Santidad] y lo
= s. Ve{o} ‹74› [que] pasastis los oficios con Su Santidad, y lo
B04 ✗ el m el lo e ni 23 to n 6 45 e no 38 n A̲ n ✗ er 124 mo e ri
que es r es po n di o mo s t ra n do lo s ‹A̲› s que en ‹124› co n si
= que ‹el› respondió mostrando los ‹A›s que en ‹124› consi
B05 ne 45 le 48 53 na di r ri er no el 51 ru 31 33 53 tu g ni 15 43 ne
de ra pe ro to da vi a si en do es te su ge go to mu y di g no de
= dera ; pero todavía, siendo este sujeto muy digno de
B06 25 do s lo m 35 r 51 e mi or mo e ✗ r mu ne r ru ti 42 n
fa vo r po r la a te n ci on co n que a cu de a su mi ni s
= favor por la atención con que acude a su minis
B07 51 47 23 g r 35 m x g 46 re e so mi or er ✗ el so g ✗
te ri o y a la r e y re se n ta ci on en que es ta y que
= terio y a la representación en que está, y que
B08 la 45 35 n mo d de 42 er mi al ne 18 re m di mi 23
pa ra la s co n ve ni en ci as de l se r vi ci o
= para las conveniencias del servicio
B09 ru g 47 e mi le g ti 23 43 lu x ne a r de s ir n 6 49
su y ri n ci pe y mi o no pu e de h a ve r in s t ru
= [de] su príncipe y mío no puede haver instru
B10 te 2 53 ta 4 r g 48 lo ri 53 du et do r er ma s 30 48 n mo
me n to ma s a y ro po si to vu el vo a en ca r ga ro s co
= mento más a propósito, buelvo a encargaros co
B11 e 52 44 x il g el 28 m me il mo e ru do r 52 54 12 35 n ir
n ti nu e is y es fo r ce is co n su vo a ti tu d la s in
= ntinuéis y esforcéis con Su {Be}atitud las in
B12 n 50 2 mi al la 45 ru ne 51 e mi or r ✗11 er mo e 28 m ti na 12 ne 35
s ta n ci as pa ra su de te n ci on a ‹✗11› en co n fo r mi da d de la
= stancias para su detención ‹✗11› en conformidad de la
B13 n g 47 te 45 n 23 m ne 41 n g ✗ 43 ne ri 4 so il lo m 42 e 34 e ma ro mo
s y ri me ra s o r de ne s y que no de si s ta is po r ni n gu n ca so co
= s primeras órdenes, y que no desistáis por ningún caso, co
B14 to er 41 33 mi 23 ✗ ir t 39 pe er ri mo d de 42 er mi al ne 18 re m di mi f
mo en ne go ci o que in c lu ye en si co n ve ni en ci as de l se r vi ci o
= mo en negocio que incluye en sí conveniencias del servicio
B15 ne ru ne e 52 na 12 g ti 23 g g na 46 il te ✗ e 50 ne 38 ✗ 46 ru 18 50 46 g re
de su de n ti da d y mi o y y da re is me que n ta de lo que re su l ta re y se
= de Su Santidad y mío ; y daréisme quenta de lo que resultare y se
B16 29 x 46 23 y 46 mi er no er 124 4
fu e re o f re ci en do en ‹124› s
= fuere ofreciendo en ‹124›. *Y sea muy reverendo en Christo padre cardenal Albornoz, mi muy charo y muy amado amigo, Nuestro Señor en vuestra continua guarda. De Madrid a 24 de julio de 1648.* *Yo el Rey.* *Pedro Coloma.*
## Copy A (images 2-3)
A01 4 ro r 46 35 mo e 52 44 r mi or ne 18 r m mo di 4 lo
s so a re la co n ti nu a ci on de l a r co vi s po
A02 ne so m ro r ur ✗ re g 48 de ar 35 n 23 6 45 n 44 e mi r
de ta r so a un que se y ro ve an la s o t ra s nu n ci a
A03 54 45 n 4 de 23 74 la ra 4 52 n 38 n 23 27 mi ol mo e
tu ra s s ve o ‹74› pa sa s ti s lo s o fi ci os co n
A04 sal g 38 ✗ ol m el lo e ni 23 to n 6 45 e no 38 n A̲ n ✗
[Su Santidad] y lo que os r es po n di o mo s t ra n do lo s ‹A̲› s que
A05 er 124 mo e ri ne 45 le 48 53 na di r ri or no el 51 m 31 53
en ‹124› co n si de ra pe ro to da vi a si on do es te r ge to
A06 tu g ni 15 43 ne 25 do s lo m 35 r 51 e mi or mo e ✗ r mu
mu y di g no de fa vo r po r la a te n ci on co n que a cu
A07 ne r m ti 42 n 51 47 23 g r 35 m x g 46 re e so mi or
de a r mi ni s te ri o y a la r e y re se n ta ci on
# (cancelled line: e ✗ r mu ne r m ti 42 n 51 47 23), then:
A08 er ✗ el so g ✗
en que es ta y que
A09 45 35 n mo d de 42 er mi al ne 18 re m di mi
ra la s co n ve ni en ci as de l se r vi ci
A10 ne m g 47 e mi le g ti 23 43 lu x ne a r de s
de r y ri n ci pe y mi o no pu e de h a ve r
A11 ir n 6 49 te 2 53 ta 4 r g 48 lo ri 53 du et do
in s t ru me n to ma s a y ro po si to vu el vo
A12 r er ma s 30 48 n mo e 52 44 x il g el 28 m me
a en ca r ga ro s co n ti nu e is y es fo r ce
A13 il mo e m de r 52 54 12 35 n ir n 50 2 mi al
is co n r ve a ti tu d la s in s ta n ci as
A14 la 45 m ne 51 e mi or r ✗11 er mo e 28 m ti na 12
pa ra r de te n ci on a ‹✗11› en co n fo r mi da d
A15 ne 35 n g 47 te 45 n 23 m ne 41 n g ✗ 43
de la s y ri me ra s o r de ne s y que no
# (cancelled: ri 4 so / tl, marked with "4"s above)
A16 ne ri 4 so il lo m 42 e 34 e ma ro mo to er 41
de si s ta is po r ni n gu n ca so co mo en ne
A17 33 mi 23 ✗ ir t 39 pe er ri mo d de 42 er mi al
go ci o que in c lu ye en si co n ve ni en ci as
A18 ne 18 re m di mi f ne m ra e 52 na 12 g ti 23 g
de l se r vi ci o de r sa n ti da d y mi o yReading
# Philip IV to Cardinal Albornoz, Madrid, 24 July 1648: established text (Spanish)
Conventions: {x} = probable reading; ‹…› = unresolved group; [x] = restored from the sense; *italics* = written in plain text in the original (opening and closing formulas). Spelling of the letter kept; punctuation and accents added.
*En carta de 24 de março avisáis el recibo de la que se os escrivió en 10 de enero* so{b}re la continuación del arçobispo de Tarso, aunque se provean las otras nunciaturas. Ve{o} ‹74› [que] pasastis los oficios con Su Santidad, y lo que ‹el› respondió mostrando los ‹A›s que en ‹124› considera ;
pero todavía, siendo este sujeto muy digno de favor por la atención con que acude a su ministerio y a la representación en que está, y que para las conveniencias del servicio [de] su príncipe y mío no puede haver instrumento más a propósito, buelvo a encargaros continuéis y esforcéis con Su {Be}atitud las instancias para su detención ‹✗11› en conformidad de las primeras órdenes, y que no desistáis por ningún caso, como en negocio que incluye en sí conveniencias del servicio de Su Santidad y mío ;
y daréisme quenta de lo que resultare y se fuere ofreciendo en ‹124›. *Y sea muy reverendo en Christo padre cardenal Albornoz, mi muy charo y muy amado amigo, Nuestro Señor en vuestra continua guarda. De Madrid a 24 de julio de 1648.* *Yo el Rey.* *Pedro Coloma.*Translation
# English translation [In your letter of 24 March you acknowledge receipt of the one written to you on 10 January] about the continuance of the Archbishop of Tarsus, even if the other nunciatures are filled. I see ‹…› [that] you made representations to His Holiness, and what he answered, showing the ‹…› that he considers in ‹…›; but nevertheless, this person being most worthy of favour for the care with which he attends to his ministry and to the representation he holds, and since for the interests of the service of his prince and mine there can be no instrument more suitable, I again charge you to continue and redouble with His Beatitude the requests for his retention ‹…›, in accordance with the first orders, and not to desist in any case, as in a business that contains interests of the service of His Holiness and mine; and you will report to me what results and whatever may arise in ‹…›. [Closing formulas in plain text:] Most reverend father in Christ, Cardinal Albornoz, my most dear and beloved friend, may Our Lord keep you. Madrid, 24 July 1648. I the King. Pedro Coloma.
OSUNA,CT.11,D.1: Haro to Peñaranda, 25 Sept 1649, enciphered for Albornoz, with its plain copy of the time (key document for K2) not prose
Key document: the cipher chapter and its plain copy of the time, used to rebuild K2 (lines 1-12) and to test it (lines 13-23); no reading of its own.
Transcription
# OSUNA,CT.11,D.1 image 3: chapter of Luis de Haro, 25 Sept 1649, enciphered for Cardinal Albornoz. Lines 1-12 = learning text # for K2 (aligned on the plain copy, image 1); lines 13-23 held out. ° = small circle above; ✗ = cross (code); ⊕ = large looped 3; ℓ = large L. L01 pa✗ no 2 61 ar ne 30 45 g re xa 18° 35 mo 2 et✗ L02 re 2 ℓ48 ne ma so 39 40 g 35 ile g 30 36 45 n L03 3 35 mo n so ne so 45 33 40 4 et✗ re me 2 55 43 el L04 lo re 0 36 re m ne te 60 m ma 37 na 12 4 38 L05 ⊕ 47 te 48 55 la 46 me 55° 47 75 re 51 2 50 m L06 x 45 mo 2 53 na n 35 n 29 x m g al 61 2 50 re L07 na m ma 38 m 3 35 ⊕ 48 de 2 me 75 la 45 L08 de m re 55 47 3 xa me m at 34 2 to de te es L09 53 mo to 38 52 x 41 2 50 2 3 re 34 45 no 4 g re° L10 el 53 43 29 x re xa me m 35 gus 55 la 46 mi L11 x 45 ta n 3 ⊕ 48 lo ri 53 la 45 55 na m 3 38 L12 ⁴55 57 no n ne 2 ℓ48 ne ma so 39 40 g ne 57 m L13 35 gus 29 x 45 ne 38 n ran 43 n ne 3 45 33 2 L14 g da 36 2 me 35 g 33 ta 2 no g 28 m 52 27 ma L15 2 no 38 n lu el 53 n 55 re lu ne x re 2 ta L16 n 3 ne 35 2 50 no n na 2 no re 35 ta 43 mo 2 L17 50 45 33 40 re mo 2 re ne 45 55° na 47 ar 53 50 L18 18 te 2 51 mo m so na n 35 n ⊕ 35 g al ne 53 L19 m 53 ra g ⊃ 37 f 4 le 48 al so de m 38 55 L20 re f 0 45 g mo to re x f x mu so re lu x ne L21 xa me m lo mo 29 2 na te 2 53 ro 0 46 53 na L22 55 2 53 re re n mu 46 55 re lu x ne g ne de ⊕ L23 48 da 0 36 te 2 51 x f x mu so m pa✗
Decryption
# OSUNA,CT.11,D.1 image 1: contemporary plain text of the passage enciphered in lines 13-23 (held-out validation of K2). la guerra fuera de los Reynos de Aragon y Valencia y tomando y fortificando los puestos que se quedieren mas adelantados dandose la mano con Tarragona se considera que quedarian totalmente cortadas las plaças de Tortosa y Lerida pero hasta ver lo que se obra y como se executa se queda la expedicion con poco fundamento sobre todo quanto se discurre que se puede y deue probablemente executar
OSUNA,CT.2,D.16: Philip IV to Albornoz, 12 Dec 1644, cipher aligned on its plain copy (key document for K1) not prose
Key document: cipher original aligned on the plain copy of the time, used to rebuild K1, which does not read the 1648 letter.
Transcription
# OSUNA,CT.2,D.16 (12 Dec 1644): learning text for K1. Cipher original (images 2-4) aligned token=value on the contemporary
# plain copy (images 6-8). ✗ = start/end mark (*); ↗ above = cancelled token (!); § above digits = number value or number syllable (§).
# image 2, lines 5-8
✗=* 28=de oc=lo 25=que 264=[su Santidad] 17=o t=s 56=re 47=fi 57=ri 17=o x=e c=n 203=[orden] 15=a e=l 15=a 4=g 55=ra 28=de a=c 3=i 32=mi x=e c=n 38=to a=c 17=o c=n 25=que ep=se θ=h 15=a ē=ll 15=a ha=ba 28=de 32=mi m=y oc=lo 25=que ec=le 56=re t=s ox=po c=n 28+=di t=s 36=ti R=s 28=de 25=que 26=que 28÷=do 15=a tt=d he=u f=r 37=ti 28÷=do
# image 2, lines 10-11 (after "en esta carta")
§=* ep=se ex=e t=s a=c 57=ri he=ue 15=a e=l 100=[Conde de Siruela] oc=lo 25=que ep=se 2=! 17=o 9=f 56=re 51=ce m=y 15=a ip=si? ox=! ox=! oc=lo ox=po tt=d ?=r? 3=e? 1=is? a=c 17=o 34=mu 42=ni a=c 15=a f=r a=c 17=o c=n x=e e=l ✗=*
# image 2, lines 20-22
✗=* ~=* 28=de ac=la 47=fi 41=ne p=z 15=a a=c 17=o c=n 25=que θ=h 15=a ep=se f=r he=ui 28÷=do m=y ip=si f=r he=ue x=e e=l 88=[Cardenal] 28=de e=l uc=u 4=g 17=o m=y oc=lo 25=que ep=se ox=po tt=d 55=ria? 1^=? a=c 17=o c=n x=e e=l 294=[tambien] x=e t=s 35=ta 56=re 31=ys 15=a tt=d he=u f=r 37=ti 28÷=do
# image 3, lines 1-3
25=que 28=de e=l 100=[Conde de Siruela] x=e c=n 36=te c=n 28=de 55=ra ac=la nil=[merced] 25=que ec=le θ=h x=e θ=h ?=cho 25=que x=e t=s 28=de 2§=dos 32=mi e=l 28==du a=c 15=a 2§=dos ox=po f=r m=u 40=na he=ve ?=z ax=pa 55=ra ox=po 41=ne f=r up=su a=c 15=a ap=sa 28=de 30=ma t=s 28=de 17=o E58=tro t=s 25!=! ec!=!
# image 3, lines 4-6
θ!=! 15!=! hi!=! 15!=! 28÷=do t=s 32=mi e=l 25=que ec=le θ=h 15=a hi=ui 15=a 56=re 32=mi 37=ti 28÷=do e=el? 309=[Virrey] 28=de Nap=[Napoles] m=y 4§=quatro 32=mi e=l x=e t=s a=c m=u 2§=dos x=e c=n 56=re c=n 35=ta s=s? m=y ex=pe c=n ip=si 17=o 41=ne t=s x=e a=c ee=le ip=si 15=a t=s 37=ti a=c 15=a t=s m=y 25=que x=e c=n
# image 3, lines 7-9 ("porque esta merced... mejor")
✗=* ox=po f=r 25=que x=e t=s 35=ta nil=[merced] ec=le x=e t=s 35=ta ha=ua θ=h x=e Sal=cha? 15=a c=n 36=te t=s 28=de x=e c=n E=t 55=ra 8=r x=e c=n a=c 17=o c=n a=c ac=la he=ue θ=h x=e 30=ma c=n 28+=da? 28=do? 15=a e=l 100=[Conde de Siruela] ec=le m=i c=n ip=si 4=g 44=nu x=e 15=a e=l 4=g m=u c=n a=c 56=re a=c 3=i 32=mi x=e c=n 38=to 28=de ex=pe c=n ip=si 17=o c=n 17=o 15=a ?=badia
# image 3, lines 10
217=[para que]? ep=se ux=pu x=e 28+=da 30=ma c=n 36=te 41=ne f=r 31=me? ol=jo f=r
# image 3, lines 11-13 (after "Dezis que por hauer")
36=te 42=ni 28÷=do ac=la m=v 17=o p=z x=e c=n x=e e=l a=c 17=o a=c ac=la he=ue m=y a=c 17=o 57=rri 28÷=do ox=po f=r 313=[vuestra] 30=ma 43=no x=e t=s 35=ta 30=ma 36=te 57=ri 15=a 28+=da 31=ys
# image 3, lines 13-19 (corrections: "3 t" = ys/is; 1 = t = s)
36=te 57=ri 15=a 28‡=da 3=y t=s 236=[quenta] 28=de bon=los? 88=[Cardenal] x=e t=s 15=a 25+=quien x=e c=n 28=de he=ue 4=g 55=ra 37=ti 47=fi a=c 15=a f=r ep=se a=c 17=o c=n a=c 15=a f=r 35=ta t=s m=y 9=p? 56=re 32=mi 17=o t=s 28=de 25=que 56=re 32=mi 37=ti t=s 31=me 33=mo 57=ri 15=a 15=a e=l 100=[Conde de Siruela] ep=se San+=auisa? 38=to 28÷=do oc=lo 56=re up=su x=e e=l 38=to x=e c=n 203=[orden] 15=a x=e t=s 38=to m=y tif=asi? 31=me 56=re 32=mi 38=to 15=a oc=lo 25=que 28=de E=l? x=e c=n 36=te c=n 28=de 56=re 3=y R=s ~=* ✗=*
# image 4, lines 1-13
✗=* 3̲=[como] x=e e=l 100=[Conde de Siruela] 25+=qui ep=so ex=pe 28+=di f=r uc=lu x=e 4=g 17=o 15=a 264=[su Santidad] felt=[alguna] 4=g 55=ra 52=ci 15=a 28=de ban=[las] 25=que x=e c=n 17=o E58=tro 297=[tiempo] 43=no ep=se θ=h 15=a hi=ui 15=a c=n 15=a e=l a=c 15=a c=n 50=za 28÷=do ✗=* 25=que 15=a 308=[vos] 17=o t=s ax=pa 56=re a=c 3=i 17=o ep=se up=su t=s ex=pe c=n 28+=di x=e ep=se ox=po f=r 43=no ax=pa 56=re 51=ce f=r a=c 17=o 28+=di 52=ci 17=o ep=so m=y 25=que ep=se 31=me 9=p 56=ro? ux=pu ip=si x=e ep=se 15=a 32=mi x=e e=l x=e t=s a=c 17=o ef=ge f=r ac=la 25=que 30=ma t=s 49=fue 56=re ep=se f=r hi=ui 28÷=do up=pu x=e t=s x=e e=l ax=pa ax=pa x=e t=s 35=ta c=n 15=a 46=fe a=c 38=to ✗=* m=y 3̲=[como] 15=a he=ue 3=y t=s x=e c=n 36=te c=n 28+=di 28÷=do x=e t=s 35=ta 30=ma 36=te 57=ri 15=a 37=ti x=e 41=ne 17=o E58=tro x=e t=s 35=ta 28÷=do up=pu x=e t=s 264=[su Santidad] ep=se 4=g m=u c=n ban=[las] m=u e=l 37=ti 30=ma t=s a=c 15=a f=r 35=ta t=s θ=h 15=a x=e n=m ex=pe p=z 15=a 28=do? 15=a a=c 17=o c=n 2!=! 51=ce 28=de f=r 31=me felt=[alguna] t=s m=y 15=a ip=si ep=se 55=ra hi=bi x=e c=n 25=que x=e t=s 38=to ep=se 28=de el=xe a=c 17=o 96=rre f=r a=c 17=o u=n 48=fo f=r ?=me 15=a ox=lo? 25=que 15=a θ=h 3=i ax=pa 56=re 52=ci x=e 56=re 15=a 32=mi t=s ?=mi ?=ni ?=s 28=de 25=que 294=[tambien] ep=se 15=a hi=ui ap=sa 15=a e=l 100=[Conde de Siruela]Decryption
# OSUNA,CT.2,D.16 (12 Dec 1644): learning text for K1. Cipher original (images 2-4) aligned token=value on the contemporary
# plain copy (images 6-8). ✗ = start/end mark (*); ↗ above = cancelled token (!); § above digits = number value or number syllable (§).
# image 2, lines 5-8
✗=* 28=de oc=lo 25=que 264=[su Santidad] 17=o t=s 56=re 47=fi 57=ri 17=o x=e c=n 203=[orden] 15=a e=l 15=a 4=g 55=ra 28=de a=c 3=i 32=mi x=e c=n 38=to a=c 17=o c=n 25=que ep=se θ=h 15=a ē=ll 15=a ha=ba 28=de 32=mi m=y oc=lo 25=que ec=le 56=re t=s ox=po c=n 28+=di t=s 36=ti R=s 28=de 25=que 26=que 28÷=do 15=a tt=d he=u f=r 37=ti 28÷=do
# image 2, lines 10-11 (after "en esta carta")
§=* ep=se ex=e t=s a=c 57=ri he=ue 15=a e=l 100=[Conde de Siruela] oc=lo 25=que ep=se 2=! 17=o 9=f 56=re 51=ce m=y 15=a ip=si? ox=! ox=! oc=lo ox=po tt=d ?=r? 3=e? 1=is? a=c 17=o 34=mu 42=ni a=c 15=a f=r a=c 17=o c=n x=e e=l ✗=*
# image 2, lines 20-22
✗=* ~=* 28=de ac=la 47=fi 41=ne p=z 15=a a=c 17=o c=n 25=que θ=h 15=a ep=se f=r he=ui 28÷=do m=y ip=si f=r he=ue x=e e=l 88=[Cardenal] 28=de e=l uc=u 4=g 17=o m=y oc=lo 25=que ep=se ox=po tt=d 55=ria? 1^=? a=c 17=o c=n x=e e=l 294=[tambien] x=e t=s 35=ta 56=re 31=ys 15=a tt=d he=u f=r 37=ti 28÷=do
# image 3, lines 1-3
25=que 28=de e=l 100=[Conde de Siruela] x=e c=n 36=te c=n 28=de 55=ra ac=la nil=[merced] 25=que ec=le θ=h x=e θ=h ?=cho 25=que x=e t=s 28=de 2§=dos 32=mi e=l 28==du a=c 15=a 2§=dos ox=po f=r m=u 40=na he=ve ?=z ax=pa 55=ra ox=po 41=ne f=r up=su a=c 15=a ap=sa 28=de 30=ma t=s 28=de 17=o E58=tro t=s 25!=! ec!=!
# image 3, lines 4-6
θ!=! 15!=! hi!=! 15!=! 28÷=do t=s 32=mi e=l 25=que ec=le θ=h 15=a hi=ui 15=a 56=re 32=mi 37=ti 28÷=do e=el? 309=[Virrey] 28=de Nap=[Napoles] m=y 4§=quatro 32=mi e=l x=e t=s a=c m=u 2§=dos x=e c=n 56=re c=n 35=ta s=s? m=y ex=pe c=n ip=si 17=o 41=ne t=s x=e a=c ee=le ip=si 15=a t=s 37=ti a=c 15=a t=s m=y 25=que x=e c=n
# image 3, lines 7-9 ("porque esta merced... mejor")
✗=* ox=po f=r 25=que x=e t=s 35=ta nil=[merced] ec=le x=e t=s 35=ta ha=ua θ=h x=e Sal=cha? 15=a c=n 36=te t=s 28=de x=e c=n E=t 55=ra 8=r x=e c=n a=c 17=o c=n a=c ac=la he=ue θ=h x=e 30=ma c=n 28+=da? 28=do? 15=a e=l 100=[Conde de Siruela] ec=le m=i c=n ip=si 4=g 44=nu x=e 15=a e=l 4=g m=u c=n a=c 56=re a=c 3=i 32=mi x=e c=n 38=to 28=de ex=pe c=n ip=si 17=o c=n 17=o 15=a ?=badia
# image 3, lines 10
217=[para que]? ep=se ux=pu x=e 28+=da 30=ma c=n 36=te 41=ne f=r 31=me? ol=jo f=r
# image 3, lines 11-13 (after "Dezis que por hauer")
36=te 42=ni 28÷=do ac=la m=v 17=o p=z x=e c=n x=e e=l a=c 17=o a=c ac=la he=ue m=y a=c 17=o 57=rri 28÷=do ox=po f=r 313=[vuestra] 30=ma 43=no x=e t=s 35=ta 30=ma 36=te 57=ri 15=a 28+=da 31=ys
# image 3, lines 13-19 (corrections: "3 t" = ys/is; 1 = t = s)
36=te 57=ri 15=a 28‡=da 3=y t=s 236=[quenta] 28=de bon=los? 88=[Cardenal] x=e t=s 15=a 25+=quien x=e c=n 28=de he=ue 4=g 55=ra 37=ti 47=fi a=c 15=a f=r ep=se a=c 17=o c=n a=c 15=a f=r 35=ta t=s m=y 9=p? 56=re 32=mi 17=o t=s 28=de 25=que 56=re 32=mi 37=ti t=s 31=me 33=mo 57=ri 15=a 15=a e=l 100=[Conde de Siruela] ep=se San+=auisa? 38=to 28÷=do oc=lo 56=re up=su x=e e=l 38=to x=e c=n 203=[orden] 15=a x=e t=s 38=to m=y tif=asi? 31=me 56=re 32=mi 38=to 15=a oc=lo 25=que 28=de E=l? x=e c=n 36=te c=n 28=de 56=re 3=y R=s ~=* ✗=*
# image 4, lines 1-13
✗=* 3̲=[como] x=e e=l 100=[Conde de Siruela] 25+=qui ep=so ex=pe 28+=di f=r uc=lu x=e 4=g 17=o 15=a 264=[su Santidad] felt=[alguna] 4=g 55=ra 52=ci 15=a 28=de ban=[las] 25=que x=e c=n 17=o E58=tro 297=[tiempo] 43=no ep=se θ=h 15=a hi=ui 15=a c=n 15=a e=l a=c 15=a c=n 50=za 28÷=do ✗=* 25=que 15=a 308=[vos] 17=o t=s ax=pa 56=re a=c 3=i 17=o ep=se up=su t=s ex=pe c=n 28+=di x=e ep=se ox=po f=r 43=no ax=pa 56=re 51=ce f=r a=c 17=o 28+=di 52=ci 17=o ep=so m=y 25=que ep=se 31=me 9=p 56=ro? ux=pu ip=si x=e ep=se 15=a 32=mi x=e e=l x=e t=s a=c 17=o ef=ge f=r ac=la 25=que 30=ma t=s 49=fue 56=re ep=se f=r hi=ui 28÷=do up=pu x=e t=s x=e e=l ax=pa ax=pa x=e t=s 35=ta c=n 15=a 46=fe a=c 38=to ✗=* m=y 3̲=[como] 15=a he=ue 3=y t=s x=e c=n 36=te c=n 28+=di 28÷=do x=e t=s 35=ta 30=ma 36=te 57=ri 15=a 37=ti x=e 41=ne 17=o E58=tro x=e t=s 35=ta 28÷=do up=pu x=e t=s 264=[su Santidad] ep=se 4=g m=u c=n ban=[las] m=u e=l 37=ti 30=ma t=s a=c 15=a f=r 35=ta t=s θ=h 15=a x=e n=m ex=pe p=z 15=a 28=do? 15=a a=c 17=o c=n 2!=! 51=ce 28=de f=r 31=me felt=[alguna] t=s m=y 15=a ip=si ep=se 55=ra hi=bi x=e c=n 25=que x=e t=s 38=to ep=se 28=de el=xe a=c 17=o 96=rre f=r a=c 17=o u=n 48=fo f=r ?=me 15=a ox=lo? 25=que 15=a θ=h 3=i ax=pa 56=re 52=ci x=e 56=re 15=a 32=mi t=s ?=mi ?=ni ?=s 28=de 25=que 294=[tambien] ep=se 15=a hi=ui ap=sa 15=a e=l 100=[Conde de Siruela]OSUNA,CT.2,D.20: Philip IV to Albornoz, 26 Jan 1645, cipher and plain copy (test of K1) not prose
Key document: transcribed before its plain copy was opened, used to test K1 (0.638 of characters recovered against a 99th percentile of 0.550 for permuted keys).
Transcription
# OSUNA,CT.2,D.20 (26 Jan 1645), image 2: held-out text for K1, transcribed before its plain copy was opened (K1 frozen 08fd8533...) ✗ x 20 26 9 58 ox 41 t R 26 10 17 20 y e 41 ox 36 29 np ap 20 37 29+ tt ep ox tt 57 15 θ 15 51 8 15 c A m 40 29 33 1 E 55 10 t 21 20 ep 40 ac 20 29 ec θ 15 1 35 29+ y p 32 e 29= 10 15 29÷ R 29 ex 20 ip 21 20 ep E 56 y e 15 8 10 y 29+ 15 40 38 29 38 ec 29÷ m oc 29 65 26 13 x 1 36 9 58 ox ip 38 29 10 t 1 E 55 35 20 29÷ 28 ac ha e 38 ic 40 ✗ 26 29÷ 15 tt he 8 37 29÷ 28 38 29÷ m y 1 hi x 20 36 20 A 15 t R y 20 36 20 29+ 29÷ 26 y 20 oc 25 9 58 ox 41 t R x 20 θ 8 29 c 15 θ R 51 8 31 8 10 y tt 15 e ep E 53 43 29 ep ap 20 37 29+ tt ep θ 15 y 10 a 57 38 15 e 10 17 20 29 28 ip 59 y ac oc 26 θ 15 ax 56 51 29÷ 10 17 13 he 42 y 20 36 10 17 33 oc θ 15 E 56 t R ap hi 29÷ at ✗
Decryption
# OSUNA,CT.2,D.20: contemporary plain copy (image 4) of the enciphered passage, used only to score K1. en que proponeys que con el Nepote de su Santidad se podria hacer alguna demostracion señalandole hasta diez mill ducados de pension sobre el Arzedianato de Toledo y lo demas que a este proposito dezis tratando de la Baltolina quedo aduertido de todo y es bien tengays entendido que en lo que proponeys en orden a hacer merced al sobrino de su Santidad se ha escrito al Conde de Siruela lo que ha parecido conbeniente como lo sabreys sauido ya
Key: key_K2.tsv
06 Sources
- Archivo Histórico de la Nobleza (Toledo), OSUNA,CT.2,D.32(1-2), Philip IV to Cardinal Albornoz, 24 July 1648: PARES record 3939398, copy A images 2–3, copy B image 5.
- Key K2: OSUNA,CT.11,D.1(1-6), Luis de Haro to the Count of Peñaranda, Madrid, 25 September 1649, plain copy image 1, cipher image 3: PARES record 3939336.
- Key K1, tried: OSUNA,CT.2,D.16, Philip IV to Albornoz, 12 December 1644, cipher images 2–4 and plain copy images 6–8 (PARES 3939415); OSUNA,CT.2,D.20, 26 January 1645, cipher image 2 and plain copy image 4 (PARES 3938842).
- Brice Dudout, Europe chiffrée: Philip IV to Cardinal Albornoz, “Do not desist in any case”, Madrid, 24 July 1648 (2026, CC BY 4.0): text, translation and notes.
- X. Arriazu García, doctoral thesis on Cardinal Albornoz’s mission in Rome (Barcelona, 2024), checked by Brice Dudout for this letter.
Folder: targets/albornoz1648/ (notes, the transcription of both copies, the line-by-line decryption, the keys K1, K2 and K2b, the key documents and the held-out texts, the validation pairs, the Spanish text and the English translation, as contributed by Brice Dudout). The text and translation are his, reproduced under CC BY 4.0.

