PACTF_2017: RSA256

Category: Points: 80 Description:

According to Wikipedia, RSA 256 can be factored on modest hardware in 35 minutes. Given the encoded public key MDwwDQYJKoZIhvcNAQEBBQADKwAwKAIhAIl47p5SrV3uMTsUAbwE0E+j+QynAY/CVq/Gf8IAOQy7AgMBAAE=, what is the similarly-encoded private key? The first 32 characters is the flag.

Hint:

And apparently YAFU can do it in 103 seconds!

Write-up

PyCrypto to the rescue!

script

Therefore, the flag is MIGpAgEAAiEAiXjunlKtXe4xOxQBvATQ.