What is a JSON wallet file and How does it work?

In this article I explain how JSON (JavaScript Object Notation) wallet files work and they interact with Ethereum.

JSON is a lightweight data interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It is often used for representing structured data, making it a popular choice for data exchange between applications and web services.

Ethereum is a decentralized blockchain platform that enables developers to build and deploy smart contracts and decentralized applications (DApps). Smart contracts are self-executing contracts with the terms of the agreement directly written into code. They are typically written in a programming language called Solidity.

In the context of Ethereum, JSON is commonly used for representing data structures related to Ethereum accounts, wallets,  transactions, smart contracts, and other blockchain-related information. The JSON format is used to serialize data into a string representation, which can be easily transmitted and stored.

For instance, when interacting with Ethereum through its JSON-RPC interface, you send JSON-formatted requests to the Ethereum node, which processes the request and returns a JSON-formatted response.

Here is an example of what an Ethereum wallet file in JSON format might look like:

“version”: 3,
“id”: “f48fb0a2-5329-4ac8-9c95-3ee1185f2cd4”,
“address”: “0x8ba1f109551bD432803012645Ac136ddd64DBA72”,
“crypto”: {
“ciphertext”: “1f6b8b90e356df7d98d25f2d44104f20b1aa550a52bf2b44164a5d69989b04f8”,
“cipherparams”: {
“iv”: “4ab2395a6e2d64e1008c152581af4c1c”
“cipher”: “aes-128-ctr”,
“kdf”: “scrypt”,
“kdfparams”: {
“dklen”: 32,
“salt”: “d8ae8bb36b962e65c62f5e5a87059da994fcfa1039525a45c6c7f3b4de8621a0”,
“n”: 8192,
“r”: 8,
“p”: 1
“mac”: “e44f39cf193ba5ce3e52f9c8b3b0852445da20c3db91e4f2cdeff58a1b4bdfed”

Let’s break down the different components:

  • "version": The version number of the wallet file format. This number indicates the structure and encryption used. In this example, it’s version 3.
  • "id": A unique identifier for this particular wallet file.
  • "address": The Ethereum address associated with this wallet, derived from the corresponding public key.
  • "crypto": The encryption-related information for securing the private key.
    • "ciphertext": The encrypted private key.
    • "cipherparams": Parameters used by the encryption algorithm.
      • "iv": The initialization vector used in the encryption process.
    • "cipher": The encryption algorithm used, in this case, “aes-128-ctr.”
    • "kdf": Key derivation function used to derive the encryption key from the passphrase.
    • "kdfparams": Parameters used by the key derivation function.
      • "dklen": The length of the derived key.
      • "salt": A random value used as additional input for the key derivation.
      • "n", "r", "p": Parameters specific to the Scrypt key derivation function.
    • "mac": A message authentication code used for data integrity verification.

Please note that wallet file formats might differ slightly based on the wallet software you are using and its version. Additionally, newer versions might be available since this page was written. Always ensure that you use wallet software from trusted sources and maintain strong security practices to safeguard your cryptocurrencies.

If you used a JSON file as a wallet to store your crypto and you can no longer access it please contact me as I may be able to recover it for you.