If a game you installed fails to launch with a "seed crypto" error, you have a few options:
A Nintendo 3DS family console with Custom Firmware (Boot9strap / Luma3DS). An SD card reader for your computer.
Check out the official guide at https://3ds.hacks.guide (safe, free, and regularly updated).
Since the official Nintendo CDN servers that distributed these seeds were closed, you can no longer use tools like PlaiCDN to download them directly. However, you have three excellent, community-driven options for obtaining a high-quality, free seeddb.bin .
Please note that using seeds and custom firmware may void your console's warranty and potentially brick your device. Proceed with caution and at your own risk. Always follow the instructions and guidelines provided by the SeedDB community and relevant development resources.