diff --git a/examples/poem.txt.crypt b/examples/poem.txt.crypt
index 6fb6eb4..46bf576 100644
--- a/examples/poem.txt.crypt
+++ b/examples/poem.txt.crypt
@@ -1,139 +1,139 @@
-Ô XFNSY UWêYWJ ! LWFSIJ âRJ ! TM ! OJ YTRGJ à LJSTZC !
-OJZSJ, NQ FAFNY JSHTW IJ QTSLX OTZWX UFWRN STZX,
-NQ S'JS F UFX HTRUYé QJ STRGWJ ;
-NQ éYFNY à HJY âLJ Tù QJ GTSMJZW KQJZWNY ;
-NQ F HTSXNIéWé QF HWTNC IJ OéXZX-HMWNXY
-YTZYJ WFDTSSFSYJ IFSX Q'TRGWJ.
+Ô CKSXD ZBêDBO ! QBKXNO âWO ! YR ! TO DYWLO à QOXYEH !
+TOEXO, SV KFKSD OXMYB NO VYXQC TYEBC ZKBWS XYEC,
+SV X'OX K ZKC MYWZDé VO XYWLBO ;
+SV éDKSD à MOD âQO Yù VO LYXROEB PVOEBSD ;
+SV K MYXCSNéBé VK MBYSH NO TéCEC-MRBSCD
+DYEDO BKIYXXKXDO NKXC V'YWLBO.
 
-NQ F INY : — « H'JXY QJ INJZ IJ UWTLWèX JY I'FRTZW.
-OéXZX, VZN ATNY YTS KWTSY HWTNY ATNW QJ KWTSY IZ OTZW.
-HMWNXY XTZWNY à VZN QJ WJUTZXXJ.
-UZNXVZ'NQ JXY RTWY UTZW STZX, OJ AJZC RTZWNW UTZW QZN ;
-IFSX XTS YTRGJFZ, ITSY O'FN QF UNJWWJ UTZW FUUZN,
-NQ R'FUUJQQJ I'ZSJ ATNC ITZHJ.
+SV K NSD : — « M'OCD VO NSOE NO ZBYQBèC OD N'KWYEB.
+TéCEC, AES FYSD DYX PBYXD MBYSD FYSB VO PBYXD NE TYEB.
+MRBSCD CYEBSD à AES VO BOZYECCO.
+ZESCAE'SV OCD WYBD ZYEB XYEC, TO FOEH WYEBSB ZYEB VES ;
+NKXC CYX DYWLOKE, NYXD T'KS VK ZSOBBO ZYEB KZZES,
+SV W'KZZOVVO N'EXO FYSH NYEMO.
 
-« XF ITHYWNSJ JXY QJ HNJQ JSYW'TZAJWY ; UFW QF RFNS,
-HTRRJ ZS UèWJ Q'JSKFSY, NQ YNJSY QJ LJSWJ MZRFNS ;
-UFW QZN STZX ANATSX JY STZX XTRRJX ;
-FZ HMJAJY IJX LJôQNJWX ITWRFSY IFSX QJZWX RFNXTSX,
-NQ IéWTGJ QJX HQJKX IJ YTZYJX QJX UWNXTSX
-JY RJY JS QNGJWYé QJX MTRRJX.
+« CK NYMDBSXO OCD VO MSOV OXDB'YEFOBD ; ZKB VK WKSX,
+MYWWO EX ZèBO V'OXPKXD, SV DSOXD VO QOXBO REWKSX ;
+ZKB VES XYEC FSFYXC OD XYEC CYWWOC ;
+KE MROFOD NOC QOôVSOBC NYBWKXD NKXC VOEBC WKSCYXC,
+SV NéBYLO VOC MVOPC NO DYEDOC VOC ZBSCYXC
+OD WOD OX VSLOBDé VOC RYWWOC.
 
-« TW NQ JXY, QTNS IJ STZX, ZSJ FZYWJ MZRFSNYé
-VZN SJ QJ HTSSFîY UTNSY, JY IFSX Q'NSNVZNYé
-WFRUJ JSHMFîSéJ, JY XTZKKWJ JY YTRGJ ;
-NQX KTSY UTZW YWTZAJW INJZ IJ YéSéGWJZC JKKTWYX ;
-NQX X'FLNYJSY JS AFNS ; NQX XTSY HTRRJ IJX RTWYX
-VZN YâYJSY QJ RZW IJ QJZW YTRGJ.
+« YB SV OCD, VYSX NO XYEC, EXO KEDBO REWKXSDé
+AES XO VO MYXXKîD ZYSXD, OD NKXC V'SXSAESDé
+BKWZO OXMRKîXéO, OD CYEPPBO OD DYWLO ;
+SVC PYXD ZYEB DBYEFOB NSOE NO DéXéLBOEH OPPYBDC ;
+SVC C'KQSDOXD OX FKSX ; SVC CYXD MYWWO NOC WYBDC
+AES DâDOXD VO WEB NO VOEB DYWLO.
 
-« XFSX QTN, XFSX GZY, XFSX LZNIJ, NQX JWWJSY NHN-GFX.
-NQX XTSY RéHMFSYX, éYFSY NLSTWFSYX ; NQX S'TSY UFX
-QJZW UFWY IJ QF LWFSIJ HTSVZêYJ.
-O'NWFN. UTZW QJX XFZAJW OJ VZNYYJ QJ XFNSY QNJZ.
-Ô RJX KWèWJX, OJ ANJSX ATZX FUUTWYJW RTS INJZ,
-OJ ANJSX ATZX FUUTWYJW RF YêYJ ! » —
+« CKXC VYS, CKXC LED, CKXC QESNO, SVC OBBOXD SMS-LKC.
+SVC CYXD WéMRKXDC, éDKXD SQXYBKXDC ; SVC X'YXD ZKC
+VOEB ZKBD NO VK QBKXNO MYXAEêDO.
+T'SBKS. ZYEB VOC CKEFOB TO AESDDO VO CKSXD VSOE.
+Ô WOC PBèBOC, TO FSOXC FYEC KZZYBDOB WYX NSOE,
+TO FSOXC FYEC KZZYBDOB WK DêDO ! » —
 
-UWêYWJ, NQ X'JXY XTZAJSZ, HFQRJ JS STX OTZWX YWTZGQéX,
-IJ QF UFWTQJ INYJ FZC FUôYWJX : — FQQJE,
-GWFAJE QJX GûHMJWX JY QJX HQFNJX ! —
-JY IJ Q'FINJZ IZ HMWNXY FZ XZUWêRJ RTRJSY :
-— Ô ANAFSY, FNRJE-ATZX ! FNRJE. JS ATZX FNRFSY,
-KWèWJX, ATZX KJWRJWJE RJX UQFNJX. —
+ZBêDBO, SV C'OCD CYEFOXE, MKVWO OX XYC TYEBC DBYELVéC,
+NO VK ZKBYVO NSDO KEH KZôDBOC : — KVVOJ,
+LBKFOJ VOC LûMROBC OD VOC MVKSOC ! —
+OD NO V'KNSOE NE MRBSCD KE CEZBêWO WYWOXD :
+— Ô FSFKXD, KSWOJ-FYEC ! KSWOJ. OX FYEC KSWKXD,
+PBèBOC, FYEC POBWOBOJ WOC ZVKSOC. —
 
-NQ X'JXY INY VZ'NQ JXY GTS I'éHQFNWJW IFSX QJZW SZNY
-HJX UJZUQJX éLFWéX QTNS IZ UWTLWèX VZN QZNY,
-ITSY Q'âRJ JXY HTZAJWYJ IJ ATNQJX ;
-UZNX NQ X'JS JXY FQQé, IFSX QJX AJSYX, IFSX QJX KQTYX,
-AJWX QJX STNWX HMJAFQJYX JY QJX XFSLQFSYX GNQQTYX,
-QJX DJZC KNCéX XZW QJX éYTNQJX.
+SV C'OCD NSD AE'SV OCD LYX N'éMVKSBOB NKXC VOEB XESD
+MOC ZOEZVOC éQKBéC VYSX NE ZBYQBèC AES VESD,
+NYXD V'âWO OCD MYEFOBDO NO FYSVOC ;
+ZESC SV C'OX OCD KVVé, NKXC VOC FOXDC, NKXC VOC PVYDC,
+FOBC VOC XYSBC MROFKVODC OD VOC CKXQVKXDC LSVVYDC,
+VOC IOEH PSHéC CEB VOC éDYSVOC.
 
-NN.
+SS.
 
-HJZC AJWX VZN HJY FUôYWJ FQQFNY, Q'TSY éLTWLé.
+MOEH FOBC AES MOD KZôDBO KVVKSD, V'YXD éQYBQé.
 
-NNN.
+SSS.
 
-TM ! YFSINX VZJ Qà-GFX, MéQFX ! HMJE HJX GFWGFWJX,
-X'éYFQJ Q'éHMFKFZI IJ YJX RJRGWJX HMFWLé,
-VZJ QJ GTZWWJFZ, WFSLJFSY XJX LQFNAJX JY XJX GFWWJX,
-KWTYYJ FZ LNGJY XTS TSLQJ Tù YTS XFSL X'JXY KNLé ;
+YR ! DKXNSC AEO Và-LKC, RéVKC ! MROJ MOC LKBLKBOC,
+C'éDKVO V'éMRKPKEN NO DOC WOWLBOC MRKBQé,
+AEO VO LYEBBOKE, BKXQOKXD COC QVKSFOC OD COC LKBBOC,
+PBYDDO KE QSLOD CYX YXQVO Yù DYX CKXQ C'OCD PSQé ;
 
-HNJQ ! YFSINX VZJ QJX HMNJSX IFSX HJ XFSL ANJSSJSY GTNWJ,
-JY VZJ QF RTZHMJ MTWWNGQJ, JXXFNR FZ ATQ OTDJZC,
-HTRRJ IFSX ZSJ WZHMJ JSYWJ JS YF GTZHMJ STNWJ
-JY GTZWITSSJ FZ XTQJNQ IFSX QJX YWTZX IJ YJX DJZC ;
+MSOV ! DKXNSC AEO VOC MRSOXC NKXC MO CKXQ FSOXXOXD LYSBO,
+OD AEO VK WYEMRO RYBBSLVO, OCCKSW KE FYV TYIOEH,
+MYWWO NKXC EXO BEMRO OXDBO OX DK LYEMRO XYSBO
+OD LYEBNYXXO KE CYVOSV NKXC VOC DBYEC NO DOC IOEH ;
 
-YFSINX VZ'éHMJAJQéJ, JY XFSX ATNC, XFSX UFZUNèWJX,
-YF YêYJ GQêRJ JXY Qà XZW ZS NSKâRJ UNJZ,
-QNAWéJ FZC ANQX FKKWTSYX, RJZWYWNJ à HTZUX IJ UNJWWJX,
-NHN, IJWWNèWJ YTN, RFWYDW, TS AJSI YTS INJZ !
+DKXNSC AE'éMROFOVéO, OD CKXC FYSH, CKXC ZKEZSèBOC,
+DK DêDO LVêWO OCD Và CEB EX SXPâWO ZSOE,
+VSFBéO KEH FSVC KPPBYXDC, WOEBDBSO à MYEZC NO ZSOBBOC,
+SMS, NOBBSèBO DYS, WKBDIB, YX FOXN DYX NSOE !
 
-HJ INJZ VZN S'JXY VZ'à YTN, RFWYDW, TS YJ QJ ATQJ !
-TS QJ QNAWJ à RFSIWNS, HJ INJZ UTZW VZN YZ RJZWX !
-IJX MTRRJX, HTRRJ YTN WJAêYZX IJ Q'éYTQJ,
-UTZW êYWJ HFWINSFZC, UTZW êYWJ XéSFYJZWX,
+MO NSOE AES X'OCD AE'à DYS, WKBDIB, YX DO VO FYVO !
+YX VO VSFBO à WKXNBSX, MO NSOE ZYEB AES DE WOEBC !
+NOC RYWWOC, MYWWO DYS BOFêDEC NO V'éDYVO,
+ZYEB êDBO MKBNSXKEH, ZYEB êDBO CéXKDOEBC,
 
-IJX UWêYWJX, UTZW FATNW IJX UFQFNX, IJX HFWWTXXJX,
-JY IJX OFWINSX Q'éYé WNFSY XTZX QJ HNJQ GQJZ,
-UTZW FWLJSYJW QJZW RNYWJ JY UTZW ITWJW QJZWX HWTXXJX,
-UTZW GTNWJ IJ GTS ANS, FXXNX UWèX I'ZS GTS KJZ,
+NOC ZBêDBOC, ZYEB KFYSB NOC ZKVKSC, NOC MKBBYCCOC,
+OD NOC TKBNSXC V'éDé BSKXD CYEC VO MSOV LVOE,
+ZYEB KBQOXDOB VOEB WSDBO OD ZYEB NYBOB VOEBC MBYCCOC,
+ZYEB LYSBO NO LYX FSX, KCCSC ZBèC N'EX LYX POE,
 
-FZ KTWGFS ITSY QF RFNS IFSX QJ RJZWYWJ JXY YWJRUéJ,
-FZ QFWWTS HMFWLé I'TW VZN UFDJ JY VZN XTZWNY,
-LWFSI INJZ ! WJYTZWSJ-YTN AJWX STZX, YêYJ HTZUéJ !
-NQX AJSIJSY OéXZX-HMWNXY ! NQX AJSIJSY OéXZX-HMWNXY !
+KE PYBLKX NYXD VK WKSX NKXC VO WOEBDBO OCD DBOWZéO,
+KE VKBBYX MRKBQé N'YB AES ZKIO OD AES CYEBSD,
+QBKXN NSOE ! BODYEBXO-DYS FOBC XYEC, DêDO MYEZéO !
+SVC FOXNOXD TéCEC-MRBSCD ! SVC FOXNOXD TéCEC-MRBSCD !
 
-NQX QNAWJSY FZ GFSINY, UTZW VZJQVZJX XFHX XTWINIJX,
-Q'éAFSLNQJ, QF QTN, Q'FZYJQ éUTZAFSYé,
-JY QF OZXYNHJ FZC DJZC XéAèWJX JY HFSINIJX,
-JY Q'éYTNQJ IZ HTJZW MZRFNS, QF AéWNYé !
+SVC VSFBOXD KE LKXNSD, ZYEB AEOVAEOC CKMC CYBNSNOC,
+V'éFKXQSVO, VK VYS, V'KEDOV éZYEFKXDé,
+OD VK TECDSMO KEH IOEH CéFèBOC OD MKXNSNOC,
+OD V'éDYSVO NE MYOEB REWKSX, VK FéBSDé !
 
-QJX GTSX OJYéX, ANAFSYX, FZ GFLSJ, TZ RTWYX, FZC KQJZAJX,
-Q'MTRRJ OZXYJ UWTXHWNY UFW HFWYTZHMJ XDQQF,
-Q'NSSTHJSY éLTWLé, QJ IJZNQ XFHWé IJX AJZAJX,
-QJX UQJZWX IJ Q'TWUMJQNS, NQX AJSIJSY YTZY HJQF !
+VOC LYXC TODéC, FSFKXDC, KE LKQXO, YE WYBDC, KEH PVOEFOC,
+V'RYWWO TECDO ZBYCMBSD ZKB MKBDYEMRO CIVVK,
+V'SXXYMOXD éQYBQé, VO NOESV CKMBé NOC FOEFOC,
+VOC ZVOEBC NO V'YBZROVSX, SVC FOXNOXD DYED MOVK !
 
-YTZY ! QF KTN, QJ XJWRJSY VZJ INJZ YNJSY XTZX XF LFWIJ,
-QJ XFNSY YJRUQJ Tù, RTZWFSY, YZ INX :NSYWTïGT,
-NQX QNAWJSY YTZY ! UZIJZW, AJWYZ ! — RFWYDW, WJLFWIJ,
-WTZAWJ YJX DJZC VZ'JRUQNY QF QZJZW IZ YTRGJFZ ; —
+DYED ! VK PYS, VO COBWOXD AEO NSOE DSOXD CYEC CK QKBNO,
+VO CKSXD DOWZVO Yù, WYEBKXD, DE NSC :SXDBYïLY,
+SVC VSFBOXD DYED ! ZENOEB, FOBDE ! — WKBDIB, BOQKBNO,
+BYEFBO DOC IOEH AE'OWZVSD VK VEOEB NE DYWLOKE ; —
 
-NQX AJSIJSY Q'FWHMJ FZLZXYJ Tù Q'MTXYNJ éYNSHJQQJ !
-NQX AJSIJSY HMWNXY, YJ INX-OJ ! JY XJX RJRGWJX QNéX !
-NQX AJSIJSY QF XZJZW VZN XZW XTS KWTSY WZNXXJQQJ,
-JY QJX HQTZX IJ XJX RFNSX, JY QJX HQTZX IJ XJX UNJIX !
+SVC FOXNOXD V'KBMRO KEQECDO Yù V'RYCDSO éDSXMOVVO !
+SVC FOXNOXD MRBSCD, DO NSC-TO ! OD COC WOWLBOC VSéC !
+SVC FOXNOXD VK CEOEB AES CEB CYX PBYXD BESCCOVVO,
+OD VOC MVYEC NO COC WKSXC, OD VOC MVYEC NO COC ZSONC !
 
-NQX AJSIJSY FZ GWNLFSI VZN HMJE QZN QJX FYYNWJ
-QJ LWFSI HWZHNKNé XZW QJX MTRRJX UJSHMé ;
-NQX AJSIJSY XF UFWTQJ, NQX AJSIJSY XTS RFWYDWJ,
-JY YTS RFWYDWJ à YTN UFW-IJXXZX QJ RFWHMé !
+SVC FOXNOXD KE LBSQKXN AES MROJ VES VOC KDDSBO
+VO QBKXN MBEMSPSé CEB VOC RYWWOC ZOXMRé ;
+SVC FOXNOXD CK ZKBYVO, SVC FOXNOXD CYX WKBDIBO,
+OD DYX WKBDIBO à DYS ZKB-NOCCEC VO WKBMRé !
 
-YFSY UTZW QJX HTZUX IJ KTZJY VZ'NQ WJçZY à QF UTWYJ !
-HéXFW ! YFSY UTZW Q'FRJS, YFSY UTZW Q'FQQéQZNF !
-YFSY UTZW QF UNJWWJ Tù ANSY MJZWYJW XF YêYJ RTWYJ !
-YFSY UTZW QJ IWFU WTZLN VZJ XF GFWGJ JXXZDF !
+DKXD ZYEB VOC MYEZC NO PYEOD AE'SV BOçED à VK ZYBDO !
+MéCKB ! DKXD ZYEB V'KWOX, DKXD ZYEB V'KVVéVESK !
+DKXD ZYEB VK ZSOBBO Yù FSXD ROEBDOB CK DêDO WYBDO !
+DKXD ZYEB VO NBKZ BYEQS AEO CK LKBLO OCCEIK !
 
-NQX AJSIJSY XJX LJSTZC RJZWYWNX, XF UFQRJ AJWYJ,
-XF UQFNJ FZ KQFSH, XTS TJNQ YTZY GFNLSé I'NSKNSN,
-XJX UQJZWX, XTS FLTSNJ, JY XF GTZHMJ JSYWTZAJWYJ,
-JY QJ HWN VZ'NQ UTZXXF : QFRRF XFGFHYMFSN !
+SVC FOXNOXD COC QOXYEH WOEBDBSC, CK ZKVWO FOBDO,
+CK ZVKSO KE PVKXM, CYX YOSV DYED LKSQXé N'SXPSXS,
+COC ZVOEBC, CYX KQYXSO, OD CK LYEMRO OXDBYEFOBDO,
+OD VO MBS AE'SV ZYECCK : VKWWK CKLKMDRKXS !
 
-NQX AJSIJSY QJ XéUZQHWJ ! NQX AJSIJSY QJX YéSèGWJX !
-QJX XéWFUMNSX HMFSYFSY FZ XJZNQ UWTKTSI IJX HNJZC,
-JY QF RèWJ IJGTZY XTZX Q'FWGWJ FZC GWFX KZSèGWJX,
-VZN, XJSYFSY Qà XTS KNQX, SJ QJAFNY UFX QJX DJZC !
+SVC FOXNOXD VO CéZEVMBO ! SVC FOXNOXD VOC DéXèLBOC !
+VOC CéBKZRSXC MRKXDKXD KE COESV ZBYPYXN NOC MSOEH,
+OD VK WèBO NOLYED CYEC V'KBLBO KEH LBKC PEXèLBOC,
+AES, COXDKXD Và CYX PSVC, XO VOFKSD ZKC VOC IOEH !
 
-TZN, HJX éAêVZJX, TZN, HJX RFWHMFSIX, TZN, HJX UWêYWJX
-F Q'MNXYWNTS IZ HWNRJ, FXXTZAN, HTZWTSSé,
-F HJ SéWTS WJUZ VZN WNY UFWRN QJX YWFîYWJX,
-ZS UNJI XZW YMWFXéFX, ZS HTZIJ XZW UMWDSé,
+YES, MOC éFêAEOC, YES, MOC WKBMRKXNC, YES, MOC ZBêDBOC
+K V'RSCDBSYX NE MBSWO, KCCYEFS, MYEBYXXé,
+K MO XéBYX BOZE AES BSD ZKBWS VOC DBKîDBOC,
+EX ZSON CEB DRBKCéKC, EX MYENO CEB ZRBIXé,
 
-FZ ATQJZW VZN YZF QJX QTNX à HTZUX IJ HWTXXJ,
-FZ UNWFYJ JRUJWJZW SFUTQéTS IJWSNJW,
-NAWJ IJZC KTNX, NRRTSIJ JSHTW UQZX VZJ KéWTHJ,
-UTZWHJFZ IFSX QJ HQTFVZJ JY QTZU IFSX QJ HMFWSNJW,
+KE FYVOEB AES DEK VOC VYSC à MYEZC NO MBYCCO,
+KE ZSBKDO OWZOBOEB XKZYVéYX NOBXSOB,
+SFBO NOEH PYSC, SWWYXNO OXMYB ZVEC AEO PéBYMO,
+ZYEBMOKE NKXC VO MVYKAEO OD VYEZ NKXC VO MRKBXSOB,
 
-NQX AJSIJSY, ô RFWYDW, QJ INJZ UJSXNK JY UâQJ
-VZN, IJGTZY XZW QF YJWWJ JY XTZX QJ KNWRFRJSY,
-YWNXYJ JY STZX XTZWNFSY IFSX STYWJ SZNY KFYFQJ,
-XZW QJ STNW LTQLTYMF XFNLSJ éYJWSJQQJRJSY !
+SVC FOXNOXD, ô WKBDIB, VO NSOE ZOXCSP OD ZâVO
+AES, NOLYED CEB VK DOBBO OD CYEC VO PSBWKWOXD,
+DBSCDO OD XYEC CYEBSKXD NKXC XYDBO XESD PKDKVO,
+CEB VO XYSB QYVQYDRK CKSQXO éDOBXOVVOWOXD !
diff --git a/src/caesar.c b/src/caesar.c
index 46a7e34..3c0a38b 100755
--- a/src/caesar.c
+++ b/src/caesar.c
@@ -1,31 +1,6 @@
 #include "caesar.h"
 
-#define BUFFER_SIZE 128
 
-/*
- This function read the file block by block until the end of it
- */
-int readFile(FILE *f, int *size, char *buffer){
-    int index = 0;
-    char c;
-    int end = 0;
-
-    do{
-        c = fgetc(f);
-        buffer[index] = c;
-        index++;
-        *size += 1;
-
-        // End of the file, we stop it
-        if (c == EOF){
-            buffer[index - 1] = '\0';
-            index = BUFFER_SIZE;
-            end = 1;
-        }
-    }while(index < BUFFER_SIZE);
-
-    return end;
-}
 /*
 	s -> path source
 	d -> path destination
diff --git a/src/caesar.h b/src/caesar.h
index fbcb691..ef2b7a6 100755
--- a/src/caesar.h
+++ b/src/caesar.h
@@ -6,7 +6,6 @@
 #include "functions.h"
 
 /* Functions */
-int foo(FILE *, int *, char *);
 int cryptCaesar(const char *, const char *, const int);
 int decryptCaesar(const char *, const char *, const int);
 
diff --git a/src/functions.c b/src/functions.c
index fcbb1eb..62c7e39 100755
--- a/src/functions.c
+++ b/src/functions.c
@@ -12,12 +12,35 @@ int fileExist(const char *path) {
 	FILE *f=NULL;
 	f=fopen(path,"r");
 
-	if(f==NULL){
+	if(f==NULL)
 		return -1;
-	}
 	fclose(f);
 	return 0;
 }
+/*
+ This function read the file block by block until the end of it
+ */
+int readFile(FILE *f, int *size, char *buffer){
+    int index = 0;
+    char c;
+    int end = 0;
+
+    do{
+        c = fgetc(f);
+        buffer[index] = c;
+        index++;
+        *size += 1;
+
+        // End of the file, we stop it
+        if (c == EOF){
+            buffer[index - 1] = '\0';
+            index = BUFFER_SIZE;
+            end = 1;
+        }
+    }while(index < BUFFER_SIZE);
+
+    return end;
+}
 /*
 	path -> path source
 	This function copy all characters of the file in the buffer
diff --git a/src/functions.h b/src/functions.h
index 526072f..877894b 100755
--- a/src/functions.h
+++ b/src/functions.h
@@ -5,8 +5,11 @@
 #include <stdlib.h>
 #include <string.h>
 
+#define BUFFER_SIZE 4092
+
 /* Functions */
 void usage();
+int readFile(FILE *, int *, char *);
 int fileExist(const char *path);
 int copyFile(const char *path, char *buffer);
 int addDataToFile(const char *data, const char *path);
diff --git a/src/polybius.c b/src/polybius.c
index 6ffd2da..042c74a 100644
--- a/src/polybius.c
+++ b/src/polybius.c
@@ -1,8 +1,12 @@
 #include "polybius.h"
 
 
-void cryptPolybius(const char *filename, const char *key){
+int cryptPolybius(const char *filename, const char *key){
     char polybius[POLYBIUS_SIZE][POLYBIUS_SIZE];
+    FILE *f = NULL, *fDst = NULL;
+    char data[BUFFER_SIZE];
+    char dataEncrypted[BUFFER_SIZE];
+    int size = 0, end = 0;
 
     generateSquarePolybius(polybius, key);
 
@@ -11,6 +15,28 @@ void cryptPolybius(const char *filename, const char *key){
             printf("%c ", polybius[i][j]);
         printf("\n");
     }
+    // Open the file
+    f = fopen(filename, "r+");
+    if (f == NULL) return -1;
+
+    /*fDst = fopen(filenameDst, "w");
+    if (fDst == NULL) {
+        fclose(f);
+        return -1;
+    }*/
+    do {
+        end = readFile(f, &size, data);
+
+	    /********* Encryption **********/
+        size = 0; 
+        memset(data, 0, BUFFER_SIZE);
+        memset(dataEncrypted, 0, BUFFER_SIZE);
+    }while(end != 1);
+	/* Close files */
+    fclose(f);
+    //fclose(fDst);
+
+    return 0;
 }
 /*
  This function fill the polybius square
@@ -49,11 +75,10 @@ void generateSquarePolybius(char polybius[POLYBIUS_SIZE][POLYBIUS_SIZE], const c
     for (int i = pos; i < ALPHABET_SIZE + pos; i++){
         char c = 'A' + n;
         if (c != 'J'){
-            
-        int res = findKeyInSquare(a, c);
+            int res = findKeyInSquare(a, c);
 
-        if (res == 0)
-            a[t++] = c;
+            if (res == 0)
+                a[t++] = c;
         }
         n++;
     }
diff --git a/src/polybius.h b/src/polybius.h
index 63b807e..bd73664 100644
--- a/src/polybius.h
+++ b/src/polybius.h
@@ -3,11 +3,12 @@
 
 #include <stdio.h>
 #include <string.h>
+#include "functions.h"
 
 #define POLYBIUS_SIZE 5
 #define ALPHABET_SIZE 26
 
-void cryptPolybius(const char *, const char *);
+int cryptPolybius(const char *, const char *);
 void generateSquarePolybius(char polybius[5][5], const char *);
 
 #endif