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๋ณด์•ˆ/CTF

[ctf-d] ์‚ฌ์ง„ ์†์—์„œ ๋นจ๊ฐ„์ƒ‰์ด...

by - ์˜คํŠธ - 2020. 12. 4.

 

์ด๋ฒˆ ๋ฌธ์ œ๋Š” png ํŒŒ์ผ์„ ์ด์šฉํ•ด์„œ ํ‘ธ๋Š” ๋ฌธ์ œ์ด๋‹ค

๋นจ๊ฐ„์ƒ‰์„ ์ค‘์š”ํ•˜๊ฒŒ ๋ด์•ผ ํ•  ๊ฒƒ ๊ฐ™๋‹ค

 

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incoherency.co.uk/image-steganography/#unhide

 

Image Steganography

Each channel (red, green, blue) of each pixel in an image is represented by an 8-bit value. To hide the secret image inside the cover image, we replace the n least significant bits of the cover pixel value with the same number of most significant bits from

incoherency.co.uk

stegsolve ๋กœ๋„ ํ’€ ์ˆ˜ ์žˆ๋Š”๋ฐ

ํ˜„์žฌ ๋‹ค์šด ๋ฐ›์€ ์ƒํƒœ๊ฐ€ ์•„๋‹ˆ๋ผ ์œ„ ์‚ฌ์ดํŠธ๋ฅผ ์ด์šฉํ–ˆ๋‹ค

 

ํŒŒ์ผ ์„ ํƒ์„ ๋ˆ„๋ฅด๊ณ  ํŒŒ์ผ์„ ์—ด๋ฉด

์•„๋ž˜์™€ ๊ฐ™์ด ์˜ค๋ฅธ์ชฝ์— flag ๊ฐ’์œผ๋กœ ์ถ”์ •๋˜๋Š” ๋ฌธ์ž์—ด์ด ๋‚˜์˜จ๋‹ค

 

์˜ค๋ฅธ์ชฝ ์‚ฌ์ง„์„ Download Full-size image๋ฅผ ๋ˆŒ๋Ÿฌ์„œ ๋ณด๋ฉด

์ด๋ ‡๊ฒŒ ๋‚˜์˜จ๋‹ค

 

tjctf{0dd5_4nd_3v3n5}

 

๋”ฐ๋ผ์„œ ์œ„์˜ ๋ฌธ์ž์—ด์„ ์ž…๋ ฅํ•˜๋ฉด

๋‹ต์ด๋ผ๊ณ  ๋‚˜์˜จ๋‹ค!

 

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