Discreet Log Contract (DLC)

A discreet log contract, or DLC, is a way to build financial contracts on Bitcoin whose payouts depend on real-world outcomes, using an oracle that publishes signed data. Proposed by MIT researcher Tadge Dryja in 2017, DLCs let two parties lock funds and settle a bet or hedge, such as a price forward, without the oracle ever knowing the contract exists.

Why it matters

Bitcoin's scripting language is deliberately limited, and DLCs show how far it can stretch. The parties precompute possible outcomes and exchange signatures that only become usable when the oracle publishes its attestation for the actual result. On chain, a DLC looks like an ordinary multisignature spend, so it inherits Bitcoin's security while revealing almost nothing publicly, which is the discreet part of the name.

The design also disciplines the oracle. Because the oracle signs data feeds rather than transactions, it cannot steal funds, and if it signs two conflicting outcomes it cryptographically exposes its own private key, creating a built-in penalty for dishonesty.

In the gold vs bitcoin debate

DLCs matter to the comparison because they answer a common criticism, that bitcoin cannot support sophisticated finance without trusted intermediaries. Hedging, forwards, and insurance-like contracts can settle directly on the chain. Gold offers nothing comparable in its physical form: every gold derivative requires an exchange, a clearinghouse, and legal enforcement, while a DLC replaces most of that stack with signatures.