cryptoPromedium

ChristmasRSA

grodno_new_year_2026

Task: Non-standard RSA challenge where the modulus n is a prime number and the encryption exponent e=4. Solution: Computed the 4th root of the ciphertext modulo the prime using two successive applications of the Tonelli-Shanks square root algorithm, then checked which of the four roots decoded to a valid flag.

$ ls tags/ techniques/
rsamodular_arithmeticprime_modulusfourth_root
tonelli_shanksmodular_square_rootprime_factorization_check
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