Derive Public Key from Private

WHAT IT DOES

Derive Public Key from Private enables you to derive public keys from Ethereum private keys. Ethereum private keys are 64-character hex strings (32 bytes) that generate a corresponding public key using elliptic curve cryptography (secp256k1). The tool takes a private key and computes the public key in both compressed and uncompressed formats. The public key is derived using the secp256k1 elliptic curve, where the public key is the result of multiplying the private key by the curve's generator point. This is essential for developers, auditors, and users who need to verify public keys, validate key pairs, or perform cryptographic operations. The tool provides clear output showing both compressed and uncompressed public key formats.

HOW TO USE

Connect your wallet using the BGWallet connector (required for context). Enter a private key in the input field—this must be a 64-character hex string (with or without 0x prefix). Click "Derive Public Key" to compute the corresponding public key. The tool displays the private key (masked) and the derived public key in both compressed and uncompressed formats. You can copy the public key to your clipboard for use. The result includes a detailed breakdown showing the private key, uncompressed public key, and compressed public key. This helps you verify key pairs and use public keys in cryptographic applications.

TECHNICAL MECHANISM

This tool implements public key derivation from a private key using the secp256k1 elliptic curve. The derivation process: (1) the private key is validated as a 64-character hex string; (2) the private key is used as a scalar value; (3) the public key is computed as the scalar multiplication of the private key by the generator point G on the secp256k1 curve; (4) the result is a point on the curve represented as an (x, y) coordinate pair; (5) the uncompressed format is 0x04 + x + y (65 bytes); (6) the compressed format is 0x02 or 0x03 + x (33 bytes), where the prefix indicates the parity of y. The tool uses ethers.js to perform the elliptic curve operations. All computation is performed locally in the browser with no data sent to external servers.

WHAT IT CANNOT SEE

This tool cannot verify that the derived public key corresponds to an actual wallet with funds or on-chain activity—it only performs key derivation. It does not support public key derivation for non-EVM chains; only Ethereum-style keys are supported. The tool cannot detect if the private key is compromised or known to be malicious; it does not check against breach databases. It does not support hardware wallet or secure enclave key derivation. The tool cannot guarantee that the derived public key is safe to use based solely on the private key format. It does not support non-standard key derivation paths or formats. The tool cannot recover the Ethereum address from the public key without additional hashing; address derivation requires hashing the public key with Keccak-256. The tool does not support compressed/uncompressed public key format selection beyond the standard.

PLEASE NOTE

This tool is designed for developers and users working with Ethereum key pairs. The private key must be 64 hex characters (32 bytes). The public key is derived using the secp256k1 curve. Both compressed and uncompressed formats are supported. The tool uses ethers.js for cryptographic operations. The derivation is performed locally in the browser and is never transmitted to external servers. The tool is read-only and does not require any on-chain interactions. Always keep private keys secure and never share them with untrusted parties. The tool is intended for testing, development, and educational purposes. For security-critical applications, always verify key pairs using trusted wallet software.