April 28, 2019
Puzzle
ChallengeServer: nc 34.92.185.118 10003File: task.py
SolutionLike babyprng, command operation has change, the output condition become strict.
123 ...
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April 28, 2019
FEAL
Differential cryptanalysis
ChallengeFile: task.py
This service gives us 50 ciphertext of our chosen plaintext, then it gives us the encrypted flag.
SolutionIt’s a typical s ...
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April 28, 2019
Puzzle
ChallengeServer: nc 34.92.185.118 10003File: task.py
This is an puzzle game, given some command to controll.
Solution123pc : program counter stac ...
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April 16, 2019
Conjugate Cycles
We are given two files: the main script horst.py, used for encryption and decryption; data.txt, which includes two plaintext-ciphertext pairs. The ...
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April 10, 2019
Intro
Hash
Length extension attack
常見的雜湊函數 md5, sha1, sha2, sha256, …
其中的過程其實跟 CBC 長得蠻像的，先切成一塊一塊的 block 去做 Hash (blocksize = 128, 256, 512, … 依算法而定)
與 Blockcipher 一樣，最後一塊長度不足的 ...
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March 30, 2019
RSA
Polynomial
Challenge1RSA challs are always easy, right? Even if N is not a integer.
file : flag.enc, pubkey.py, rsa.sage
Some Facts and Definitions From Al ...
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November 11, 2018
Ethereum
DoS
ChallengeOur team has prepared for an ICO. However, we are worried that there might a way to exploit the smart contracts in such a way that new in ...
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November 11, 2018
Ethereum
storage
ChallengeYour goal is to subscribe as a VIP.
Target: http://142.93.103.129:3000
This challenge is an Storage Allocation Description in smart co ...
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June 12, 2018
CBC
bitflip
Challenge這是一個猜數字的題目，你送出去的東西，他會幫你用 AES.CBC decrypt.
因為不知道 key，密文解密成什麼已經不重要了，我不會知道
還好 iv 可以自己控制，iv 能幹嘛？
他會幫我 xor 我被解密的亂數呀。
能做的就是好好控制 iv ，測試我 “被解密的亂數 ...
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June 12, 2018
CBC
challenge
server.py
題目 ：
連線過去輸入1, 你會發現，他的密文長度600多：flag 大約 32~48 bytes
當你試著輸入2, 你會發現，這個題目不會給你反應＠＠
AES-CBC with Random IV
不知道這題要幹嘛，反正仔細看看裡面有什麼東西 ...
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