I doubt if books like "Code Book" or any book on history of crptography ever mentions this one
Also, note that the language of the Mlechas mentioned there in, seems to hold a key for Indus script decipherment
Mahabharata > Adi Parva > Jatugriha Parva CXLVII
The ITRANS of the Devanagiri from http://sanskrit.gde.to/mirrors/mahabharata/txt/01.txt
vidurasya suhR^itkashchitkhanakaH kushalaH kva chit .
vivikte pANDavAnrAjannida.n vachanamabravIt .. 1..\prahito vidureNAsmi khanakaH kushalo bhR^isham .
pANDavAnAM priya.n kAryamiti kiM karavANi vaH .. 2..\prachchhanna.n vidureNoktaH shreyastvamiha pANDavAn .
pratipAdaya vishvAsAditi ki.n karavANi vaH .. 3..\kR^iShNapakShe chaturdashyA.n rAtrAvasya purochanaH .
bhavanasya tava dvAri pradAsyati hutAshanam .. 4..\mAtrA saha pradagdhavyAH pANDavAH puruSharShabhAH .
iti vyavasitaM pArtha dhArtarAShTrasya me shrutam .. 5..\ki.n chichcha vidureNokto mlechchha vAchAsi pANDava .
tvayA cha tattathetyuktametadvishvAsakAraNam .. 6..\uvAcha ta.n satyadhR^itiH kuntIputro yudhiShThiraH .
abhijAnAmi saumya tvA.n suhR^idaM vidurasya vai .. 7..\shuchimAptaM priya.n chaiva sadA cha dR^iDhabhaktikam .
na vidyate kaveH ki.n chidabhiGYAnaprayojanam .. 8..\yathA naH sa tathA nastvaM nirvisheShA vaya.n tvayi .
bhavataH sma yathA tasya pAlayAsmAnyathA kaviH .. 9..\ida.n sharaNamAgneyaM madarthamiti me matiH .
purochanena vihita.n dhArtarAShTrasya shAsanAt .. 10..\sa pApaH koshavAMshchaiva sasahAyashcha durmatiH .
asmAnapi cha duShTAtmA nityakAlaM prabAdhate .. 11..\sa bhavAnmokShayatvasmAnyatnenAsmAddhutAshanAt .
asmAsviha hi dagdheShu sakAmaH syAtsuyodhanaH .. 12..\samR^iddhamAyudhAgAramida.n tasya durAtmanaH .
vaprAnte niShpratIkAramAshliShyeda.n kR^itaM mahat .. 13..\ida.n tadashubhaM nUnaM tasya karma chikIrShitam .
prAgeva viduro veda tenAsmAnanvabodhayat .. 14..\seyamApadanuprAptA kShattA yA.n dR^iShTavAnpurA .
purochanasyAviditAnasmA.nstva.n vipramochaya .. 15..\sa tatheti pratishrutya khanako yatnamAsthitaH .
parikhAmutkirannAma chakAra sumahadbilam .. 16..\chakre cha veshmanastasya madhye nAtimahanmukham .
kapATayuktamaGYAta.n samaM bhUmyA cha bhArata .. 17..\purochana bhayAchchaiva vyadadhAtsa.nvR^itaM mukham .
sa tatra cha gR^ihadvAri vasatyashubha dhIH sadA .. 18..\tatra te sAyudhAH sarve vasanti sma kShapAM nR^ipa .
divA charanti mR^igayAM pANDaveyA vanAdvanam .. 19..\vishvastavadavishvastA va~nchayantaH purochanam .
atuShTAstuShTavadrAjannUShuH paramaduHkhitAH .. 20..\na chainAnanvabudhyanta narA nagaravAsinaH .
anyatra vidurAmAtyAttasmAtkhanaka sattamAt .. 21..\
For the entire translation, see http://www.sacred-texts.com/hin/m01/m01148.htm
Here's the relevant portion
"He that knoweth the schemes his foes contrive in accordance with the dictates of political science, should, knowing them, act in such a way as to avoid all danger. He that knoweth that there are sharp weapons capable of cutting the body though not made of steel, and understandeth also the means of warding them off, can never be injured by foes. He liveth who protecteth himself by the knowledge that neither the consumer of straw and wood nor the drier of the dew burneth the inmates of a hole in the deep woods. The blind man seeth not his way: the blind man hath no knowledge of direction. He that hath no firmness never acquireth prosperity. Remembering this, be upon your guard. The man who taketh a weapon not made of steel ( i.e., an inflammable abode) given him by his foes, can escape from fire by making his abode like unto that of a jackal (having many outlets). By wandering a man may acquire the knowledge of ways, and by the stars he can ascertain the direction, and he that keepeth his five (senses) under control can never be oppressed y his enemies."