<s>
Many	O
undeciphered	B-Algorithm
writing	I-Algorithm
systems	I-Algorithm
exist	O
today	O
;	O
most	O
date	O
back	O
several	O
thousand	O
years	O
,	O
although	O
some	O
more	O
modern	O
examples	O
do	O
exist	O
.	O
</s>
<s>
Khitan	O
large	O
script	O
and	O
Khitan	B-Algorithm
small	I-Algorithm
script	I-Algorithm
–	O
Khitan	O
,	O
10th	O
century	O
,	O
not	O
fully	O
deciphered	O
.	O
</s>
<s>
Cretan	B-Language
hieroglyphs	I-Language
,	O
c	O
.	O
2100	O
BC	O
.	O
</s>
<s>
Linear	O
A	O
and	O
Cretan	B-Language
hieroglyphs	I-Language
are	O
both	O
believed	O
to	O
be	O
an	O
example	O
of	O
the	O
Minoan	O
language	O
.	O
</s>
<s>
Voynich	B-Library
manuscript	I-Library
,	O
carbon	O
dated	O
to	O
the	O
15thcentury	O
.	O
</s>
<s>
Ancient	B-Algorithm
inscriptions	I-Algorithm
in	I-Algorithm
Somalia	I-Algorithm
,	O
According	O
to	O
the	O
Ministry	O
of	O
Information	O
and	O
National	O
Guidance	O
of	O
Somalia	O
,	O
inscriptions	O
can	O
be	O
found	O
on	O
various	O
old	O
Taalo	O
Tiiriyaad	O
structures	O
.	O
</s>
<s>
Mixtec	O
–	O
Mixtec	O
,	O
12th	O
–	O
14th	O
century	O
,	O
the	O
pictographic	O
elements	O
which	O
accompany	O
the	O
script	O
are	O
well-understood	O
,	O
but	O
semantic	B-Application
and	O
linguistic	O
components	O
of	O
the	O
script	O
proper	O
are	O
less	O
well	O
known	O
.	O
</s>
<s>
Rongorongo	B-Language
–	O
Rapa	O
Nui	O
(	O
aka	O
Easter	O
Island	O
)	O
,	O
before	O
1860	O
.	O
</s>
<s>
False	O
writing	O
cannot	O
be	O
deciphered	O
because	O
it	O
has	O
no	O
semantic	B-Application
meaning	O
.	O
</s>
<s>
Another	O
similar	O
concept	O
is	O
that	O
of	O
undeciphered	O
cryptograms	B-Application
,	O
or	O
cipher	B-Application
messages	O
.	O
</s>
<s>
Of	O
course	O
any	O
cryptogram	B-Application
is	O
intended	O
to	O
be	O
undecipherable	O
by	O
anyone	O
except	O
the	O
intended	O
recipient	O
so	O
vast	O
numbers	O
of	O
these	O
exist	O
,	O
but	O
a	O
few	O
examples	O
have	O
become	O
famous	O
and	O
are	O
listed	O
in	O
list	O
of	O
ciphertexts	O
.	O
</s>
