Unlocking Chuck’s Lost Doge: How BTCRecover + Cursor AI + Grok 3 Cracked a Decade-Old Wallet Ten years ago, my friend Chuck bought a pile of Dogecoin for the meme. He stored it in a MultiDoge wallet and forgot the password, leaving the .wallet and .key files on an old hard drive. Today Chuck’s riding high. After grinding through flight school and logging countless hours, he’s just become a pilot for a major airline, living his dream. Years ago, I tried cracking his wallet and failed, but the puzzle has haunted me ever since. Determined to make his career high even sweeter, I used Cursor AI with xAI’s Grok 3 to recover his wallet, generating over 4 billion password variations, extracting the private key, and sweeping the funds into Coinomi. It wasn’t a coding slog—I kept telling Cursor when things broke, and Grok 3 fixed it. By optimizing BTCrecover, I hit ~250,000 passwords per second on my MacBook Air M1, cracking it in just 5 hours. The 1-hour effort I put into setup—here’s how I solved it. MultiDoge, a Dogecoin client forked from MultiBit Classic, encrypts its private key in the .key file using OpenSSL’s AES-256-CBC, secured by a user password and a custom salt. There’s no BIP39 seed phrase—just a 256-bit key behind a lost string. Chuck’s password, was likely between 5 to 9 characters, maybe a word with numbers or a symbol. I chose BTCrecover, an open-source tool for wallets like MultiDoge. Using Cursor AI, powered by Grok 3, I cloned the repo and started customizing. I asked Cursor to generate scripts for password candidates he had told me about years ago. The first list, a few million passwords, missed. I told Cursor, “No good, expand it.” Grok 3 added leetspeak, keyboard errors, and a bunch of other patterns to generate a 72GB wordlist, 4 billion potential passwords. To make BTCrecover fly, I optimized it for speed on my MacBook Air M1, reaching ~250,000 passwords per second. Here’s how: • Multi-threading: I configured BTCrecover to use multiple worker threads, leveraging the M1’s cores for parallel password checks, boosting throughput over single-threaded runs. • Efficient Hashing: MultiDoge’s MD5-based hashing (~3 iterations) is fast, letting the M1 tear through checks without GPU help. • Optimized Password Lists: I pre-generated password lists (over 4 billion), reading them in large batches to minimize disk I/O and skip on-the-fly computation. These tweaks, guided by Grok 3’s suggestions when I hit issues, let BTCrecover sustain ~250,000 passwords per second, making 4 billion checks manageable in just 5 hours. The tool extracted the .key file’s salt and ran parallel AES decryption, with checkpointing to save progress. Privacy was critical. I disabled Cursor’s codebase sharing in its privacy settings, keeping my work local. I ran BTCrecover outside Cursor’s interface, so it never touched the .key file or private key. Scripts executed on my MacBook, command-line only, fully isolated. When BTCrecover faltered—like misparsing the .key file’s salt—I told Cursor, “It’s not reading right, fix it.” Grok 3 tweaked salt extraction or thread balancing, keeping things smooth. After ~5 hours, BTCrecover cracked it: a 9-character password. The .key file decrypted, yielding a 256-bit private key in hex. MultiDoge’s format doesn’t work with modern wallets, so I needed Wallet Import Format (WIF) for Dogecoin. I told Cursor to write a conversion script, and Grok 3 delivered, handling the mainnet byte, double SHA-256 checksum, and Base58 encoding. Dogecoin supports compressed and uncompressed WIFs, so I generated both. The first WIF failed, so I told Cursor, “Checksum’s off, fix it.” Grok 3 debugged the encoding, matching Dogecoin’s spec. With the compressed WIF, I used Coinomi’s “sweep paper wallet” feature. Chuck’s Dogecoin balance loaded, untouched in 10 years. I sent the coins to a new Coinomi wallet with a secure seed phrase, then moved them to another wallet for safety. The funds are secure, job done. Can't wait to tell Chuck in the morning. The win is how Cursor AI and Grok 3 turned my years-long itch into reality. I said, “This isn’t right,” and curiosity delivered, from optimized brute-forcing to a swept wallet. It’s proof AI can crack real problems. Not a huge haul, but 12,402 DOGE for 1 hour of setup effort? Totally worth it. Proof: Thanks maintainers of + @elonmusk + @grok + @xai + @cursor_ai