A .json extension is not a format
JSON is a container syntax. A legacy presale backup, an execution-account keystore and a validator keystore can all use it while protecting different kinds of material. Identify the originating application and approximate creation date alongside the file’s structure. A matching field name is a clue, not proof of authenticity or completeness.
Three useful clues
| Shape | Clues | Next reference |
|---|---|---|
| Legacy presale | encseed and ethaddr | Historical presale tooling |
| Web3 V3 | version 3; crypto/Crypto; cipher and kdf settings | Web3 secret storage |
| Validator | version 4; crypto modules including kdf, checksum and cipher | ERC-2335 |
Do not convert by renaming
Changing a filename or version number does not convert encrypted data into another wallet format. Preserve the original and inspect a copy. Avoid pasting the complete file into a web search, public issue tracker or online JSON formatter. Even an encrypted backup deserves controlled handling.
What V3 actually describes
Web3 secret storage records an encrypted private key and the parameters needed to derive an encryption key from a password. It identifies the cipher and key-derivation function rather than promising a password-reset mechanism. The specification distinguishes PBKDF2 and scrypt parameters. Validator keystores follow a separate specification and should not be passed to an account-wallet tool just because both are JSON.
Practice without a real backup
The synthetic format lab uses deliberately incomplete, invented objects. It teaches the distinction without reading any wallet file. If your backup does not fit a known shape, preserve that uncertainty rather than forcing it into the nearest category.