│ Category: Cryptography
│ Difficulty: Easy
│ Points: 100
│ Author: Imattas aka Zemi
│ Challenge ID: 31
│ Solves: 310
────────────────────────────────────────────────────────────────────────────────
--[ Challenge Description ]--
-- text --
We have a government seized Boro Wallet with 51.42 bc before any transactions occurred. Sadly, the suspect refuses to give us the private key.
Can you retrieve the key?
Boro Coin uses standard secp256k1 ECDSA.
A transaction hash is generated by taking the SHA-256 of the string format: "sender:recipient:amount" (Colons included!)
The JSON will give you all the transactions ever made with the wallet.
Note: This challenge does not contain a flag. You will need to submit the private key (lowercase hex, no prefix) as the flag.
Example: boroCTF{7f2a4b...}
────────────────────────────────────────────────────────────────────────────────
--[ Provided Materials ]--
:: Files
- Source file 1
https://boroctf.com/files/064518008a83db2615188bfa1470b802/transactions.json
────────────────────────────────────────────────────────────────────────────────
--[ Recon / Initial Analysis ]--
This archive-style writeup preserves the official prompt and materials from
BoroCTF challenge 046. The numbered source file did not include expanded solve
notes for approach, findings, or flag, so this page keeps the verified challenge
material without adding unverified exploit steps.
Use the prompt, connection details, and any listed files above as the starting
point for a replay or future expanded solve.
────────────────────────────────────────────────────────────────────────────────
--[ Exploitation / Solution ]--
No solve transcript was present in the numbered source file. If a verified solve
is added later, this section should be replaced with the actual commands,
payloads, scripts, and final flag path.
────────────────────────────────────────────────────────────────────────────────
--[ Key Takeaways ]--
- The challenge prompt and provided materials are preserved in the site's
BoroCTF archive.
- The page avoids inventing solve details where the source entry only contained
scaffolded note fields.
- Author metadata is normalized to Imattas aka Zemi.