Undeciphered writing systems

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Undeciphered writing systems are proposed writing systems for which no decipherment has achieved broad acceptance in the specialist literature.^[1] Most examples are ancient, but a small number are medieval or modern.^[1] In some cases the evidence is too limited to determine whether the marks represent a true writing system, a form of proto-writing, or a set of non-linguistic symbols; modern artistic traditions such as asemic writing likewise imitate the appearance of writing while intentionally withholding stable linguistic meaning.^[2]

Difficulties in decipherment commonly arise from one or more of the following: the absence of bilingual texts or other external “anchors” (such as securely identifiable names or dates); uncertain or unknown underlying languages (including possible language isolates); small corpora; and damage or loss of archaeological context needed to test proposed readings against use and genre.^[1] In some corpora, an additional difficulty is uncertainty over whether the signs constitute writing at all (as has often been argued for the Vinča symbols).^[3]

Various decipherment claims have been proposed for several items listed here (including the Indus script, the Phaistos Disc, and the Isthmian/Epi-Olmec script), but these proposals remain disputed and have not achieved broad acceptance in the scholarly literature unless otherwise noted.^[4][5]

This list includes writing systems and sign systems that are commonly described in reliable secondary sources as undeciphered, not fully deciphered, or of uncertain decipherment. Items of disputed authenticity or disputed status as writing are explicitly identified as such.

Certain forms of proto-writing remain undeciphered and, because of limited evidence and uncertain linguistic affiliation, may never be deciphered.

• Jiahu symbols – Peiligang culture, China, c. 6600 – c. 6200 BCE.^[6][7]
• Damaidi symbols – Damaidi, China; earliest estimated dates range from the Paleolithic to approximately 3000 years ago.^{[citation needed]}
• Dadiwan symbols – Dadiwan, China, c. 5800 – c. 5400 BCE.^{[citation needed]}
• Banpo symbols – Yangshao culture, China, 5th millennium BCE.^[8]
• Jiangzhai symbols – Yangshao culture, China, 4th millennium BCE.^{[citation needed]}
• Dawenkou symbols – Dawenkou culture, c. 2800 – c. 2500 BCE.^[9]
• Longshan symbols – Longshan culture, China, c. 2500 – c. 1900 BCE.^[10][11][12]

• Wucheng symbols – Wucheng culture, China, c. 1600 BCE.^{[citation needed]}

• Sawveh – Guangxi, China; reported as possible proto-writing or writing in some local traditions and secondary sources; status as a historical writing system is uncertain.^[12]

• 
  Jiahu symbols
• 
  Banpo symbols
• 
  Longshan symbols
• 
  Sawveh

• Vinča symbols – Neolithic Europe (Central and Southeastern Europe), c. 4500 – c. 4000 BCE. Often treated as proto-writing or symbolic marks rather than confirmed writing.^[13][14]

• 
  Vinča symbols

• Indus script – c. 2800 – c. 1900 BCE.^[15][16][4]
• Vikramkhol inscription – c. 1500 BCE.^{[citation needed]}
• Megalithic graffiti symbols – c. 1000 BCE – c. 300 CE; proposed as possible writing and sometimes hypothesized as related to the Indus tradition, though this remains debated.^[17]
• Pushkarasari script – Gandhara, 3rd century BCE to 8th century CE.^{[citation needed]}
• Shankhalipi – c. 4th – c. 8th century CE.^{[citation needed]}

• 
  Indus script
• 
  Vikramkhol inscription
• 
  Pushkarasari script
• 
  Shankhalipi

• Proto-Elamite script – c. 3100 – c. 2900 BCE.^[18]
• Jiroft script – c. 2200 BCE.^{[citation needed]}
• Byblos syllabary – Byblos, c. 1700 BCE.^{[citation needed]}
• Trojan script – Troy (Early Bronze Age); status disputed and it is unclear whether the marks constitute a single writing system or writing at all.^[19]

• 
  Proto-Elamite script
• 
  Byblos syllabary

• Ba–Shu scripts – 5th to 4th century BCE.^{[citation needed]}
• Khitan large script and Khitan small script – Khitan, 10th century; partially understood but not fully deciphered.^{[citation needed]}

• 
  Ba script
• 
  Khitan large script
• 
  Khitan small script

• Singapore Stone – fragment of a sandstone slab inscribed with an ancient Southeast Asian script, possibly Old Javanese or Sanskrit; at least 13th century, possibly as early as 10th–11th century.^{[citation needed]}

• 
  Singapore Stone

• Oxus script – c. 2200 BCE.^{[citation needed]}
• Issyk inscription – Kazakhstan, c. 4th century BCE.^{[citation needed]}
• Kushan script – c. 2nd century BCE – c. 7th century CE; partially deciphered, with recent proposals identifying a substantial portion of the sign inventory and phonetic values in the scholarly literature.^[20]

• 
  Issyk inscription

• Cretan hieroglyphs – c. 2100 BCE.^[21][22][23]
• Linear A – c. 1800 – c. 1450 BCE; the sign values are often transcribed using correspondences with Linear B, but the underlying language remains unknown and most texts are not understood.^[24]
• Phaistos Disc – c. 1850 – c. 1300 BCE; no consensus decipherment, though numerous proposals exist.^[25][26]
• Cypro-Minoan syllabary – c. 1550 BCE.^[27]
• Grakliani Hill script – Grakliani Hill, c. 11th – c. 10th century BCE.^{[citation needed]}
• Paleohispanic scripts – several scripts are partly deciphered (sign values largely known), but many inscriptions and underlying languages remain only partly understood; inclusion and degree of decipherment vary by script.^{[citation needed]}
  • Southwest Paleohispanic script – from c. 700 BCE.^[28]
• Sitovo inscription – c. 300 – c. 100 BCE.^[29]
• Alekanovo inscription – c. 10th – c. 11th century CE.^{[citation needed]}
• Rohonc Codex – 17th–19th centuries.^{[citation needed]}
• Voynich manuscript – radiocarbon dated (parchment) to the early 15th century.^[30]
• An inscription in the Pisa Baptistery – a short medieval religious inscription attested in Tuscany; the script/language and interpretation remain debated in the literature.^[31]

• 
  Cretan hieroglyphs
• 
  Phaistos disc
• 
  Linear A
• 
  Cypro-Minoan syllabary
• 
  Southwest Paleohispanic script
• 
  Sitovo inscription

• The Starving of Saqqara – a privately held sculpture claimed to be ancient and bearing an unidentified inscription; provenance and authenticity have been questioned, and the markings are not securely established as an ancient writing system.^[32]
• Wadi el-Hol inscriptions – Egypt; early alphabetic inscriptions (often dated to the late Middle Kingdom, roughly early 2nd millennium BCE) with proposed readings but no universally accepted full decipherment; frequently discussed in relation to Proto-Sinaitic script.^[33][34]

• Eghap script – Cameroon, c. 1900; partially deciphered.^{[citation needed]}
• Ancient inscriptions in Somalia – inscriptions reported on Taalo Tiiriyaad structures; independent archaeological verification and interpretation vary in the literature.^[35]

• Quipu – Knotted-cord recording devices used in the Inca Empire and by several earlier Andean societies such as the Wari. Possible Proto-Quipus have been found in Paracas and Caral-Supe, though these remain controversial. Quipus continued to be used in certain regions during the early colonial period and, in limited contexts, into the modern era. They are widely accepted as record-keeping devices; whether they constitute “writing” (and what kind) remains debated. Some recent scholarship argues that particular colonial-period quipu assemblages display features consistent with logosyllabic encoding and proposes tentative readings of specific elements; however, these claims remain controversial and do not represent a broadly accepted decipherment.^[36] In another case, six early colonial quipus from the Santa Valley, Peru, have been correlated with a contemporaneous Spanish administrative document, making the connection a possible test case for linking quipus to alphabetic texts.^[37][38]

• 
  Quipu

• Olmec hieroglyphs – c. 1000 – c. 400 BCE; sometimes proposed as a “mother script” in broader origin theories, though the evidence and relationships remain debated.^[39]
• Zapotec hieroglyphs – c. 500 BCE – c. 800 CE; often described as logosyllabic, with varying degrees of interpretation.^[40]
• Ñuiñe hieroglyphs – c. 400 – c. 800 CE; similar to Zapotec and possibly an offshoot in the Mixteca Baja; often described as logosyllabic.^[41]
• Isthmian (Epi-Olmec) hieroglyphs – c. 400 BCE – c. 500 CE; partial readings have been proposed, but the overall decipherment remains disputed.^[42]
• Izapan hieroglyphs – Late Preclassic; often proposed as related to Isthmian traditions and later Lowland Maya developments; status remains uncertain.^[43]
• Teotihuacan hieroglyphs – c. 100 BCE – c. 700 CE; sometimes described as partially logosyllabary and partially a pictography; its relationship to earlier traditions is debated. Descendants include the Mixteca-Puebla Postclassic tradition.^[44]
• Classic Gulf Coast hieroglyphs – Early Classic to Early Postclassic; often discussed as related to central Mexican traditions.^[45]
• Cotzumalhuapa hieroglyphs – c. 0 – c. 1000 CE; sometimes discussed as influenced by Teotihuacan and Lowland Maya traditions; seemingly of autonomous local development, though ultimately related to all other mesoamerican writing systems. Interpretation remains limited.^[46]
• Epiclassic/Early Postclassic hieroglyphs of Xochicalco, Cacaxtla, Teotenango, Tula and Chichén Itzá – generally treated as part of broader regional glyphic traditions; many elements remain only partially understood. Intermediary between the Teotihuacan Classic Period hieroglyphs and their Mixteca-Puebla descendants of the Middle and Late Postclassic. ^[47][48]

Many Mesoamerican glyphic traditions remain only partly understood, with the Classic/Lowland Maya script being the best-attested and most extensively deciphered. Other regional traditions (including those often grouped under “Mixteca-Puebla” or pictorial-historical codex traditions ultimately descended from the Teotihuacan tradition, most notably represented by Aztec hieroglyphs and Mixtec hieroglyphs ) have been interpreted in the literature to varying extents, but are not universally recognised as a writing system, with some researchers considering it a mostly non-linguistic form of expression^[49]. Yet, in recent years new research has appeared confirming the existence of logosyllabic elements ("glyphs") intermixed with pictorial images.^[50][41] Nevertheless, new approaches have emerged, integrating the pictorial images as key in the linguistic interpretation of all elements in the codices, alongside the logograms and phonograms. These pictorial images would represent greater units of meaning, namely semantograms, also called embedded meanings, than a lexeme (logograms) or a sound (phonogram) which would become of paramount importance to achieve a coherent linguistic message in the codices.^[51] Thus, Mixteca-Puebla writing would constitute a form of non-linear writing.

• 
  La Venta Stele 19
• 
  Olmec colossal head in La Venta (possible name glyph on forehead)
• 
  Zapotec script
• 
  Isthmian/Epi-Olmec inscription
• 
  Izapan tradition (Tak'alik Ab'aj)
• 
  Cotzumalhuapa tradition

• Kōhau Rongorongo – Rapa Nui. Attested by the 19th century; often hypothesized to encode language but remains undeciphered.^[52]

• 
  Kōhau Rongorongo

A related concept is that of false writing systems, which appear to be writing but are not. False writing cannot be deciphered because it has no stable semantic meaning. This includes many forms of asemic writing created for artistic purposes. A prominent example is the Codex Seraphinianus.

Another related concept is that of undeciphered cryptograms or cipher messages. These are not writing systems per se, but enciphered forms of texts written in known systems. Some have become famous and are listed in list of ciphertexts.

• Proto-Elamite (archived CDLI link)
• Vinča signs (The Old European Script: Further evidence – Shan M. M. Winn)