March
4th,
2019
First, let’s take a look at the file :
My first idea was to use xortool :
xortool -b basic_crypto
We get a new picture :
As we can see on the picture, there is a hint “too low”. Maybe the length of the picture is modified. So I use tweakpng to resize the picture :
And we obtained another picture ! I open it with gimp and use the miror’s effect :
I used Online OCR converter to convert the text on the png to a text file.
wo, ooJ
KVXHA3DFMFZWC3TUEBXG64RAMRUW22LOOV2GS33OEBSXQY3FNRWGK3TDMUQGC4DBOJ2G2ZLOORZSA2LNOBZ
HKZDFNZRWKIDUNBSSA3LFOQQG4ZLXFYQEI4TBO4QHAYLSOQQHI2DFNUQGQZJAMFXCA5DPEBUGKIDSN5XWMIDPN
ZWHSLRAJV2XG2LDEBWGKYLWMUQHGYLZEBSG633SOMQGQ2LNFYQFI33SMUQGE4TFMQQGM33SNUQGSZRAONU
WO2BAMNQXGZJAMFZSAZDPFYQFG5DBPFUW4ZZANBSSA3TPEBWG633LNFXGOIDJMYQGI3ZAN5YGS3TJN5XC4ICTM
VXHI2LNMVXHI4ZAO5QXSIDVNZSGK4TTORXW6ZBAMVXGIIDQMFZHI2LBNRUXI6JAMFXGIIDINFZS4IAKBJKHK4TOMV
SCA2LUEB2XAIDTNBXXK3DEEBXG6IDWMFWGYZLZEBRW65LTNFXCA2DFFYQFG4DFMFVWS3THEBXHK3LFOJXXK4ZAM
FZWWIDENFSCA2DPOJZGSYTMMUQHAYLDNNQWOZLTEBZWK5BOEBAXG2DBNVSWIID,MVZHGZLMMYQGQYLTEBSGS
43UMFXHIIDDMFXCA43UOVSGSZLEEBWXE4ZOEBGGKZBAORUGK4TFMZXXEZJANF2HGIDNNFSGI3DFORXW4IDQMVZ
HAZLUOVQWYIDGOVWGM2LMNRSWIIDQOJXXM2LTNFXW4,DGOJQW423OMVZXGLRAIZWGCZZANFZSASKTJFKEIVCV
PM2G4XZUNZTTG3C7GBTF6MLNGRTTGX3IGNZDGIL5FYQFG3LBNRWCA2DFEBSHEYLXNYQGCZTUMVZCAYLNN5XGOID
FOZSXE6JAORUHEZLFEBXG6LRAIFWGYI DI MF3GS3THEBRH K5BAPFXXKI DFMR3WC4TEEBTW
K3TJOVZSA5DIN5 2WO2BA
OJSW2YLSNMQG63TFFYQAUCSJNZZWS4DJMRUXI 6JAORUG KI
DTOVTGM2LDNFSW45BAMRUXGY3SMV2GS33OEBUW
24DSOVSG K3TDMUQHEZLTN5WH K5DJN5XCA43JOIQGQ2LNEBSG
KY3JONUXMZLMPEXCAUDSN5RWKZLEEBUG65ZAM
FXHSI DFNZTW CZ3FMQQHM2LTNF2G64ROEBCXQ4DMMFUW4ZLEEBYHE33QOJUWK5DZEBXWMZRAN5 2XI I
DQMVZH
AZLUOVQWYI DINFZSA6LPOUXCARTFMVWCA43
PNRSCA33GMYQGMZLMOQQG4YLZEBZG643FEBWWK5BAPFXXKLRAK
5SSA43 PEBSW45DSMVQX, 2LFOMQGG5LMORUXMYLUMVSCAYLTORXW42LTNBSW , ,
DJOMXCAV3BOMQHG2LTORSXE
, DGN5ZCAZTFO4QGY3 3OM5SXE , DNOJZSA43VMRSG K3RAORQWYZLOOQQGEZLDN5WWKLRA ,
RXW4ZJANVQXSI DCN5
ZG K , DROVUX , , DFOZUWY , DPNRSCA 3UNRSS4 ,GMYQGY2LLMVWHS , DBNUQG6ZRAMJSWC5LUPEQH
,YLTORSXGLRA
AZLUOVQWYIDINFZSA6LPOUXCARTFMVWCA43PNRSCA33GMYQGMZLMOQQG4YLZEBZG643FEBWWK5BAPFXXKLRAK
5SSA43PEBSW45DSMVQXI2LFOMQGG5LMORUXMYLUMVSCAYLTORXW42LTNBSWIIDJOMXCAV3BOMQHG2LTORSXE
Let’s try to decode this base32 cipher with Multisolver :
Flag :
ISITDTU{4n_4ng3l_0f_1m4g3_h3r3!}