Notes on “A Friendly Introduction to Number Theory”
Writeup for Crypto Problems in De1CTF 2019
- (easy) xorz: recover key from stream cipher
- (medium) Babylfsr: reverse a lfsr given (nearly) 2n outputs
- (medium) Baby RSA: crack a nesting RSA
Writeup for Crypto Problems in CyBRICS CTF 2019
- (easy) Zakukozh: decipher an img file encrypted by Affine Cipher
- (medium) Fast Crypto: optimize a brute-force algorithm using mathematical theories
Writeup for Crypto Problems in SCTF 2019
- (medium) warmup: forge AES message to get verified
- (medium) babygame: RSA Broadcast Attack with Linear Padding & forge
Writeup for EasyRSA in 2019神盾杯
- (medium) easyRSA: tackle RSA using 3 attacks
Writeup for Crypto Problems in 2019西湖论剑决赛（复现）
- (easy) RSA: find p+q given n, e, d
- (easy) VVVV: Vigenere Cipher
Writeup for Crypto Problems in 第三届强网杯
- (hard) copperstudy: tackle 6 RSA challenges concerning Coppersmith method
- (easy) 强网先锋-辅助: recover p from two different n1, n2 generated by the same p
Reproduction Report: CVE-2018-2844
Writeup for Babyrsa in GUETCTF 2019
- (easy) baby_rsa: calculate n according to given relationship of p and q