CTF-Crypto題目safer-than-rot13的WriteUp
safer-than-rot13
題目資訊
附件：
cry100
XMVZGC RGC AMG RVMG HGFGMQYCD VT VWM BYNO, NSVWDS NSGO RAO XG UWFN AF
HACDGMVWF. AIRVFN AII AMG JVRRVC-XVMC, FYRBIG TVIZ ESV SAH CGQGM XGGC
RVMG NSAC A RYIG TMVR NSG SVWFG ESGMG NSGO EGMG XVMC WCNYI NSG HAO
FVRG IVMH JARG MVWCH NV NAZG NSGR VTT NV EAM. OVWM TIAD YF "CV NSYF
YF CVN JMOBNV RO HGAM", YC IVEGMJAFG, EYNS WCHGMFJVMGF YCFNGAH VT
FBAJGF, FWMMVWCHGH XO NSG WFWAI "TIAD" NAD ACH JWMIO XMAJGF. GCUVO.
解題思路
1.根據題目名稱提示，考慮使用rot13解碼
cat cry100 | tr A-Z N-ZA-M >out.txt
2.解碼後，發現依然沒有有用的資訊，嘗試進行詞頻分析https://quipqiup.com/
KZIMTP ETP NZT EIZT UTSTZDLPQ IG IJZ OLAB, AFIJQF AFTB ENB KT HJSA NS
UNPQTZIJS. NVEISA NVV NZT WIEEIP-KIZP, SLEOVT GIVM RFI FNU PTDTZ KTTP
EIZT AFNP N ELVT GZIE AFT FIJST RFTZT AFTB RTZT KIZP JPALV AFT UNB
SIET VIZU WNET ZIJPU AI ANMT AFTE IGG AI RNZ. BIJZ GVNQ LS "PI AFLS
LS PIA WZBOAI EB UTNZ", LP VIRTZWNST, RLAF JPUTZSWIZTS LPSATNU IG
SONWTS, SJZZIJPUTU KB AFT JSJNV "GVNQ" ANQ NPU WJZVB KZNWTS. TPHIB.
3.得到有用資訊和flag
BROKEN MEN ARE MORE DESERVING OF OUR PITY, THOUGH THEY MAY BE JUST AS DANGEROUS. ALMOST ALL ARE COMMON-BORN, SIMPLE FOLK WHO HAD NEVER BEEN MORE THAN A MILE FROM THE HOUSE WHERE THEY WERE BORN UNTIL THE DAY SOME LORD CAME ROUND TO TAKE THEM OFF TO WAR. YOUR FLAG IS "NO THIS IS NOT CRYPTO MY DEAR", IN LOWERCASE, WITH UNDERSCORES INSTEAD OF SPACES, SURROUNDED BY THE USUAL "FLAG" TAG AND CURLY BRACES. ENJOY.
破碎的人更值得我們同情，盡管他們可能同樣危險。幾乎所有人都是普通的普通人，他們從未離他們出生的房子超過一英裡，直到有一天某位領主來将他們帶去戰争。您的旗幟是“不，親愛的，這不是加密貨币”，小寫，下劃線代替空格，周圍是通常的“旗幟”标簽和花括号。請享用。
FLAG
no_this_is_not_crypto_my_dear