IB EVMJGASVCJNM, C TRKTGIGRGIAB EIJNPV IT C OPGNAZ AQ PBEVMJGIBS KM YNIEN RBIGT AQ JWCIBGPHG CVP VPJWCEPZ YIGN EIJNPVGPHG, CEEAVZIBS GA C QIHPZ TMTGPO; GNP "RBIGT" OCM KP TIBSWP WPGGPVT (GNP OATG EAOOAB), JCIVT AQ WPGGPVT, GVIJWPGT AQ WPGGPVT, OIHGRVPT AQ GNP CKAXP, CBZ TA QAVGN. GNP VPEPIXPV ZPEIJNPVT GNP GPHG KM JPVQAVOIBS GNP IBXPVTP TRKTGIGRGIAB. GNP QWCS IT CTIOJWPTRKTGIGRGIAB
in cryptography a substitution cipher is a method of encrypting by which units of plaintext are replaced with ciphertext according to a fixed system the units may be single letters the most common pairs of letters triplets of letters mixtures of the above and so forth the receiver deciphers the text by performing the inverse substitution the flag is asimplesubstitution
Key = fuckmybrain
Caesar Cipher (ROT13)
rotated 13 positions
lowercase and uppercase letters are
> cat data.txt | tr a-zA-Z n-za-mN-ZA-M
cat packagev1 | base64 -d > packagev2
file packagev2 ...Zip archive data
unzip packagev2
file package.txt.Z.xz.xxd.tar.bz2 ..bzip2 compressed data,
bzip2 -d package.txt.Z.xz.xxd.tar.bz2
file package.txt.Z.xz.xxd.tar ..POSIX tar archive
tar -xvf package.txt.Z.xz.xxd.tar
file package.txt.Z.xz.xxd ..ASCII text
xxd ..is a hexdump tool
xxd -r package.txt.Z.xz.xxd > package.txt.Z.xz
file package.txt.Z.xz ..XZ compressed data
xz --decompress package.txt.Z.xz
file package.txt.Z ..compressd data 16 bits
uncompress package.txt.Z
cat package.txt
North Pole: The Frostiest Place on Earth
Win!!
RSA Wiener
REF: BrainfuckHTB
decrypt given p, q and e
final: python
convert to hex, then ascii
> pt = 123
> str(hex(pt))
> str(hex(pt)[2:-1]).decode('hex')
flag!
bash loop base64
for i in $ seq(0 9); do echo -n '| base64-d';done
cat pwdbackup.txt | base64 -d | etc...
python loop base64
Decode base64 for 10 times!!
import base64
inp_string = "Vm0wd2QyUXlVWGxWV0d4WFlURndVRl="
times = 10
for i in range(times):
inp_string = base64.b64decode(inp_string)
out_string = inp_string.decode('UTF-8')
print(out_string)
You have the Encryption AND Decryption .. but need the KEY
Example: Brainfuck:
