Hashed TimeLock Contract (HTLC)

Sep 19, 2024 | Updated Sep 19, 2024

What is a Hashed TimeLock Contract (HTLC)?

A Hashed TimeLock Contract is essentially a type of smart contract that allows for secure, time-bound asset transfers between two parties on separate ledgers or blockchains.

It ensures that assets are only exchanged once both parties fulfill the contract’s conditions, which mainly revolve around revealing a secret key. HTLC is important because it enables trustless, cross-chain exchanges without relying on intermediaries.

HTLC Lightning Network

In the context of the Lightning Network, HTLCs are critical for enabling fast, small-scale Bitcoin transactions without needing the main blockchain. They allow users to send and receive Bitcoin across interconnected channels securely, without relying on trust between participants.

For example, let’s say Alice wants to send Bitcoin to Carol but has no direct connection. Alice can route her payment through Bob using HTLC, ensuring that Bob can’t intercept the funds and all participants get paid only when the conditions are met.

By setting a time limit, the contract guarantees that if either party doesn’t act in time, the transaction is reversed, protecting everyone involved.

This makes HTLC a cornerstone of scalable blockchain solutions like the Lightning Network, where fast, secure payments are essential.