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files  Crypto  EasyCrpyto

system32.kr의 EasyCrpyto 문제 풀이 입니다. 아마 EasyCrypto 인데 Crpyto로 오타내신듯 하네요.

EasyCrypto.md

It is Very Easy Crypto!

### Find the Crpyto FLAG!

Ex) FLAG{ABC} <= FLAG(upper)

Make my pental

어... crypto인지 crpyto인지 으어어어어ㅓㅓㅓㅓㅓㅓㅓ

혀튼 문제파일을 봅시다.

Crypto.txt

WKHUH LV D GLIIHUHQFH EHWZHHQ YROXQWDUB VLPSOLFLWB DQG YROXQWDUB SRYHUWB. YROXQWDUB VLPSOLFLWB VHHPV YHUB PXFK WR PH D PRYHPHQW DEVRUEHG LQWR WKH PBWK RI WKH VXVWDLQDEOH PLGGOH FODVV. SRYHUWB ZDV QRW VHHQ DV SDUWLFXODUOB DWWUDFWLYH, VR LQVWHDG LW EHFDPH VLPSOLFLWB. WKHUH LV D ILQH, FRPSHOOLQJ, EXW KRUULEOB GHVWUXFWLYH VWRUB. LW’V D VWRUB WKDW SURYLGHV HDVH RI PLQG WR HYHUB RQH RI XV ZKR KDV D ZHDNQHVV IRU DOO WKH FRPIRUWV WKDW WKH GRPLQDQW VBVWHP JUDQWV XV ZKLOH VLPXOWDQHRXVOB FUHDWLQJ WKH LOOXVLRQ RI SHUVRQDO UHVSRQVLELOLWB EB WHOOLQJ XV WKDW ZH QHHG D PDVVLYH HIIRUW WR HOHFW D JRYHUQPHQW WKDW ZLOO SURPLVH XV D XWRSLDQ IXWXUH DQG D VXVWDLQDEOH, EURDG-EDVHG SHULRG RI HFRQRPLF JURZWK. BRX FDQ VWLOO EXB BRXU ZDB WR KDSSLQHVV, ZKLFK LV MXVW VOLJKWOB GLIIHUHQW IURP ZKDW WKH PDLQVWUHDP SUHVFULEHV. YROXQWDUB SRYHUWB, RQ WKH RWKHU KDQG, LV EUXWDOOB KRQHVW. WKHUH’V QR JHWWLQJ DURXQG WKH ZRUG “SRYHUWB”?LW PHDQV OHVV PRQHB, OHVV HQHUJB, OHVV UHVRXUFHV. LW PHDQV WKDW BRX FDQ’W EXB BRXU ZDB RXW RI BRXU SUHGLFDPHQW, DQG WKDW LQVWHDG BRX KDYH WR OHDUQ KRZ WR OLYH LQ D IXQGDPHQWDOOB GLIIHUHQW ZDB. LW PHDQV OHVV FRPIRUW DQG OXAXUB, DQG OHDUQLQJ KRZ WR OLYH ZHOO ZLWK WKDW. LQ RWKHU ZRUGV, LI YROXQWDUB VLPSOLFLWB LV WKH HOHFWULF FDU, YROXQWDUB SRYHUWB LV ZDONLQJ WR ZKHUH BRX QHHG WR JR. ZDONLQJ LV KRQHVWB. WKH HOHFWULF FDU LV VWRUBWHOOLQJ. IODJ{MXOLXV_FDHVDU_FUBSWR_VFRUH_1}

매우 긴 문자열이지만 우리가 살펴볼 곳은 오직 맨 마지막입니다.

IODJ{MXOLXV_FDHVDU_FUBSWR_VFRUH_1}

플래그 형식임을 확인할 수 있습니다.

IODJ가 FLAG가 되어야 합니다.

일단 매우매우 쉬운 암호라고 했으니 카이사르로 풀어보겠습니다.

23회 shift 한 결과 I가 F에 맞춰지면서 복호화가 되었습니다. (사실 처음에 치환암호인줄 알고 삽질하다가 힌트가 너무 없어서 엇 카이사르 아닐까 하고 시도해보니 맞았던...)

there is a difference between voluntary simplicity and voluntary poverty. voluntary simplicity seems very much to me a movement absorbed into the myth of the sustainable middle class. poverty was not seen as particularly attractive, so instead it became simplicity. there is a fine, compelling, but horribly destructive story. it’s a story that provides ease of mind to every one of us who has a weakness for all the comforts that the dominant system grants us while simultaneously creating the illusion of personal responsibility by telling us that we need a massive effort to elect a government that will promise us a utopian future and a sustainable, broad-based period of economic growth. you can still buy your way to happiness, which is just slightly different from what the mainstream prescribes. voluntary poverty, on the other hand, is brutally honest. there’s no getting around the word “poverty”?it means less money, less energy, less resources. it means that you can’t buy your way out of your predicament, and that instead you have to learn how to live in a fundamentally different way. it means less comfort and luxury, and learning how to live well with that. in other words, if voluntary simplicity is the electric car, voluntary poverty is walking to where you need to go. walking is honesty. the electric car is storytelling. flag{julius_caesar_crypto_score_1}

플래그는 대문자라고 했으니 대문자로 바꿔주었습니다.

FLAG : FLAG{JULIUS_CAESAR_CRYPTO_SCORE_1}

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