These are shared across all 3DS units. They are used to decrypt encrypted content like CIAs (CTR Importable Archives) and CDN (Content Delivery Network) content.
Whether you see the public availability of 3DS AES keys as a security failure or a liberation of digital archaeology depends on your perspective. For the homebrew community, it is the difference between a locked black box and an open book. 3ds aes keys
To modify a 3DS game (e.g., translate a Japan-exclusive RPG into English), you must first decrypt the ROM using the Title Key. Once decrypted, you can edit assets, repack them, and re-encrypt (or run them decrypted on a CFW console). These are shared across all 3DS units
For years, the 3DS held. Then came the cataclysm: the BootROM exploits. translate a Japan-exclusive RPG into English)