https://chocorusk.hatenablog.com/entry/2025/01/26/180123

https://github.com/maple3142/My-CTF-Challenges/blob/master/AlpacaHack Round 9/ffmac/README.md

RSAMPC: [11 solves]

Author: chocorusk

I calculated the RSA public key using multi-party computation.

[rsampc.tar.gz](<https://alpacahack-prod.s3.ap-northeast-1.amazonaws.com/7f99d733-d5e2-4c75-8776-572b4c0616b8/rsampc.tar.gz>)

rsampc.tar.gz

addprimes: [13 solves]

Author: chocorusk

addprimes in PARI/GP is useful for implementing RSA decryption.

nc 34.170.146.252 20209

[addprimes.tar.gz](<https://alpacahack-prod.s3.ap-northeast-1.amazonaws.com/765d2356-bb4a-4df0-998b-38702801554f/addprimes.tar.gz>)

addprimes.tar.gz

Equivalent Privacy Wired: [2 solves]

Author: chocorusk

I heard that WEP is vulnerable, so I modified it a bit.

nc 34.170.146.252 38920

[server.py](<https://alpacahack-prod.s3.ap-northeast-1.amazonaws.com/6454c60d-f353-48e7-90f6-67fa71f16907/server.py>)

server.py

ffmac: [2 solves]

Author: maple3142

just a simple message authentication code based on finite fields.

nc 34.170.146.252 52907

[server.sage](<https://alpacahack-prod.s3.ap-northeast-1.amazonaws.com/bb11fc22-def3-4b8b-982b-34ea2a48c880/server.sage>)

server.sage