circusmonkey404's Security Site

RingZeroCTF – Cyrpto – Can you understand this sentence Objective : get the flag Solution: Bubble Babble I had to google around on this one a bit to figure out that it was a bubble babble. I had never heard of it but it is just essentially another way of encoding HEX so that it looks at bit more palatable to the human eye. I tried my Google-Fu to find an online decrypter/Deoder but didn’t find anything, I did however find this site with a PHP script that can both endcode and decode bubble babble http://bohwaz.net/p/Bubble-Babble-CLI-encoder-decoder I downloaded the bubblebabble.php I dumped the message into a text file to feed into the PHP script root@kali:~/Downloads# echo "xipak-comok-repuk-vanik-dytuk-dimyk-sinyx" >> bubble.txt Then I pushed that through the PHP decoding script root@kali:~/Downloads# php ./bubblebabble.php   -d bubble.txt hackingbubble

PicoCTF2018 Cryptography RSA-Madlibs Objective : We ran into some weird puzzles we think may mean something, can you help me solve one? Connect with nc 2018shell.picoctf.com 50652 Solution : Hello, Welcome to RSA Madlibs Keeping young children entertained, since, well, nev3r Tell us how to fill in the blanks, or if it's even possible to do so Everything, input and output, is decimal, not hex #### NEW MADLIB #### q : 93187 p : 94603 ##### WE'RE GONNA NEED THE FOLLOWING #### n IS THIS POSSIBLE and FEASIBLE? (Y/N):y This is possible because n = pq so we just simply multiply the numbers to get q #### TIME TO FILL IN THE MADLIB! ### n: 8815769761 YAHHH! That one was a great madlib!!! #### NEW MADLIB #### p : 81203 n : 6315400919 ##### WE'RE GONNA NEED THE FOLLOWING #### q IS THIS POSSIBLE and FEASIBLE? (Y/N):y This is also possible since n=pq  transitively we know that q=n/p #### TIME TO FILL IN THE MADLIB! ### q: 77773 YAHHH! That one was

PicoCTF2018 Cryptography caesar cipher 2 Objective: Can you help us decrypt this message [1] ? We believe it is a form of a caesar cipher. You can find the ciphertext in /problems/caesar-cipher-2_0_372a62ea0204b948793a2b1b3aeacaaa on the shell server. Hint: (1) You'll have figure out the correct alphabet that was used to encrypt the ciphertext from the ascii character set (2) <a href="https://www.asciitable.com/">ASCII<a> Table Solution: Here is the output for the nc session  ^WQ]1B4iQ/SaO@M1W>V3`AMXcABMO@3\BMa3QC`3k Solution: So I assume this is a shift but on ASCII instead of the alphabet This site can decrypt these for us https://www.dcode.fr/ascii-shift-cipher shift 110 picoCTF{cAesaR_CiPhErS_juST_aREnT_sEcUrE}

PicoCTF2018  Cryptography  hertz 2 Objective: This flag has been encrypted with some kind of cipher, can you decrypt it? Connect with nc 2018shell.picoctf.com 12521. got this as the result of the nc Let's decode this now! Yws deruo caign pib qekvh ifsa yws ljzm tix. R ujn'y cslrsfs ywrh rh heuw jn sjhm vaiclsk rn Vrui. Ry'h jlkihy jh rp R hilfst j vaiclsk jlasjtm! Iojm, prns. Wsas'h yws pljx: vruiUYP{hechyryeyrin_urvwsah_jas_yii_sjhm_xknrcraynf} the hint says "These kinds of problems are solved with a frequency that metric some analysis" Solution: so let's use letter frequency to try and crack it, some super high level analysis I don't see any double letters that would be like OO in English but we can borrow some logic from the enigma crack, just like every message the Germans were sending ended with Heil Hitler, we know the format of the flag the flag always starts with picoCTF so we can be fairly certain that the letters  vruiUYP

PicoCTF2018  Cryptography  blaise's cipher Objective: My buddy Blaise told me he learned about this cool cipher invented by a guy also named Blaise! Can you figure out what it says? Connect with nc 2018shell.picoctf.com 46966. Solution: So a google search of blaise cipher brought up links to a Vigenere cipher created by Blaise Vigenere. It looks like this is more advanced Cesar cipher with a variable rotation based on a key word This site is a decoder for these ciphers https://www.dcode.fr/vigenere-cipher here is the output of connecting via nc Encrypted message: Yse lncsz bplr-izcarpnzjo dkxnroueius zf g uzlefwpnfmeznn cousex bls ltcmaqltki my Rjzn Hfetoxea Gqmexyt axtfnj 1467 fyd axpd g rptgq nivmpr jndc zt dwoynh hjewkjy cousex fwpnfmezx. Llhjcto'x dyyypm uswy ybttimpd gqahggpty fqtkw debjcar bzrjx, lnj xhizhsey bprk nydohltki my cwttosr tnj wezypr uk ehk hzrxjdpusoitl llvmlbky tn zmp cousexypxz. Qltkw, tn 1508, Ptsatsps Zwttnjxiax, tn nnd wuwv Puqtgxfahof

PicoCTF2018 Crypto Caesar cipher Objective: This is one of the older ciphers in the books, can you decrypt the message [1] ? You can find the ciphertext in /problems/caesar-cipher-1_0_931ac10f43e4d2ee03d76f6914a07507 on the shell server. Solution: Just a simple ceasar cipher shift I used this site to decrypt https://www.dcode.fr/caesar-cipher It is just a 15 shift justagoodoldcaesarcipherobyujeez picoCTF{JUSTAGOODOLDCAESARCIPHEROBYUJEEZ} ** this one took longer than it should have.... It  took me a while to realize the key needed to be lower case**

picoCTF Crypto Hertz Objective: Here's another simple cipher for you where we made a bunch of substitutions. Can you decrypt it? Connect with nc 2018shell.picoctf.com 48186. Solution: ------------------------------------------------------------------------------- ilahpgwe bqpq ue clkp mjgh - eksewuwkwula_iudbqpe_gpq_eljrgsjq_rvgeipxugy ------------------------------------------------------------------------------- igjj yq uebygqj. elyq cqgpe ghl-aqrqp yuav blx jlah dpqiueqjc-bgruah juwwjq lp al ylaqc ua yc dkpeq, gav alwbuah dgpwuikjgp wl uawqpqew yq la eblpq, u wblkhbw u xlkjv eguj gslkw g juwwjq gav eqq wbq xgwqpc dgpw lm wbq xlpjv. uw ue g xgc u bgrq lm vpuruah lmm wbq edjqqa gav pqhkjgwuah wbq iupikjgwula. xbqaqrqp u muav yceqjm hplxuah hpuy gslkw wbq ylkwb; xbqaqrqp uw ue g vgyd, vpunnjc alrqysqp ua yc elkj; xbqaqrqp u muav yceqjm uarljkawgpujc dgkeuah sqmlpq ilmmua xgpqblkeqe, gav spuahuah kd wbq pqgp lm qrqpc mkaqpgj u yqqw; gav qedqiugjjc xbqaqrqp y

PicoCTF2018 - Crypto- Crypto Warmup 2 Objective: Cryptography doesn't have to be complicated, have you ever heard of something called rot13? cvpbPGS{guvf_vf_pelcgb!} Solution: let's solve this in bash I'm just going to use tr translate to a ROT13 echo "cvpbPGS{guvf_vf_pelcgb}" | tr '[A-Za-z]' '[N-ZA-Mn-za-m]' 1st shot @pico-2018-shell:~$ echo "cvpbPGS{guvf_vf_pelcgb!}" | tr '[A-Za-z]' '[N-ZA-Mn-za-m]' -bash: !}: event not found OK it doesn't like to translate "!" because its not alpha we are trying. let's try it again without the ! (I'll just add it back in after the translation) @pico-2018-shell:~$ echo "cvpbPGS{guvf_vf_pelcgb}" | tr '[A-Za-z]' '[N-ZA-Mn-za-m]' picoCTF{this_is_crypto} let's not forget to add the ! back in picoCTF{this_is_crypto!} ** just a bit of explanation on the tr command what were doing here is remapping the al

PicoCTF2018 - Crypto- Crypto Warmup Objective: Crpyto can often be done by hand, here's a message you got from a friend, llkjmlmpadkkc with the key of thisisalilkey. Can you use this table [1]  to solve it?. Table:     A B C D E F G H I J K L M N O P Q R S T U V W X Y Z    +---------------------------------------------------- A | A B C D E F G H I J K L M N O P Q R S T U V W X Y Z B | B C D E F G H I J K L M N O P Q R S T U V W X Y Z A C | C D E F G H I J K L M N O P Q R S T U V W X Y Z A B D | D E F G H I J K L M N O P Q R S T U V W X Y Z A B C E | E F G H I J K L M N O P Q R S T U V W X Y Z A B C D F | F G H I J K L M N O P Q R S T U V W X Y Z A B C D E G | G H I J K L M N O P Q R S T U V W X Y Z A B C D E F H | H I J K L M N O P Q R S T U V W X Y Z A B C D E F G I | I J K L M N O P Q R S T U V W X Y Z A B C D E F G H J | J K L M N O P Q R S T U V W X Y Z A B C D E F G H I K | K L M N O P Q R S T U V W X Y Z A B C D E F G H I J L | L M N O P Q R S T U V W X Y