Crypto Guides

Can ‘Discreet Log Contracts’ Potentially Gear Bitcoin for DeFi?


The term “DeFi” has gained significant popularity in the cryptocurrency space since the beginning of 2020. Over hundreds of projects have already been implemented on Ethereum based on the intersection of blockchain and decentralized financial systems. The appealing ones being collateralized stablecoins and derivatives products.

Given that the ecosystem can be feasibly built on a smart contract using Ethereum, the concept of open finance cannot be excluded from Bitcoin. For instance, sidechains like RSK (rootstock) can upgrade their smart contract capabilities, enabling more advanced financial products to build on Bitcoin.

That said, there are some other enthralling ideas on extending the Bitcoin’s structure to more sophisticated financial applications. Out of which, one exciting proposal that is in the talks over a few years is the discreet log contracts.

Bitcoin for DeFi – A Sustainable Approach?

Developers are uncertain about bringing in DeFi applications on Bitcoin. People believe that the reason for its significant value to date is due to its simple, stripped-down reliable design.

Contrariwise, ideas such as the lightning network for Bitcoin has resulted in an entirely new design for it. With the feature of layered scaling, applications can be still be created without hindering the security model of bitcoin’s core protocol.

The success has hence opened doors for exploring applications that help leverage bitcoin without having to compromise on its existing design.

But limitations exist…

The most significant trade-off is the complexity of DeFi applications. RSK could no doubt prove to be a valuable sidechain for Bitcoin, but federated peg sidechain essentially requires trust in controlling the chain.

Additional improvements in the underlying technology can reduce trust even further. The compelling DeFi projects on the Ethereum protocol is not possible to incorporate on Bitcoin’s protocol without compromising trust.

Cutting through the interesting project ideas, let’s get our feet wet to understand and generalize the concept of Discreet Log Contracts.

What are Discreet Log Contracts?

Proposed by Thaddeus Dryja, discreet log contracts are an ecosystem for minimizing the trust in blockchain oracles – assimilating data from external sources to the blockchain. Discreet log contracts pivot using Schnorr signatures to disguise the agreed upon contract information from the oracles.

This creates a scenario where payouts on data (public) are possible between three parties. The advantages of it being better security and flexible contracts without having to compromise on the trust.

Useful Ecosystem?

When applied to DeFi, the two parties can maximize their discreet log contracts and unleash the potential of derivatives, futures, and several other financial instruments. More advanced financial products when knotted to bitcoin, institutional practices like hedging risk on assets can become viable through the Bitcoin’s network. With the reliance on oracle-sourced data for payouts, micro-insurance contracts are possible using the discreet log contracts.


The prevalence of DeFi systems built on the Ethereum is hindering the notion of open financial products for Bitcoin. But considering the robust security model and consensus rules, the Bitcoin network does put forth a captivating medium for decentralized finance. And discreet lot contracts are an appealing tool that can help developers develop a more advanced open finance ecosystem with Bitcoin.

Crypto Guides

How Beneficial Are ‘Watchtowers’ In Diminishing Malicious Activity on Bitcoin LN?


The concept of watchtowers was originated from the Lightning Network (LN) and has improved drastically since its launch as Bitcoin’s Lightning Network seems to be growing at a large scale in the P2P payments system.

What are Watchtowers?

Watchtowers are fundamentally an ecosystem of third parties employed by the users to outsource monitoring the on-chain transactions of their lighting channels.

Watchtowers can be related to “watchdogs” of the Bitcoin blockchain that play the role of identifying and penalizing malicious users for cheating other users within the channel. Precisely, they verify whether a participant in a channel has properly broadcasted a prior channel state. If they find it malicious, they can claim back the funds after closing the LN channel with an invalid state.

Since it is a third-party service, they receive funds from their clients. The clients sometimes outsource the channel monitoring to multiple watchtowers, in case of failure from one. The LN channel users must check the status of correlation between off-chain channels and on-chain activity occasionally. Watchtowers 24/7 keep an eye on the security risk posed by any invalid LN channel, however.

How Exactly do Watchtowers Work? 

In simple terms, watchtowers are third parties that monitor their clients’ Bitcoin blockchain all day long. They check for any ambiguity between on-chain and off-chain channels with invalid states.

Here is a basic flow of how watchtower mechanism functions between two users in a common payment channel.

  • Joe sends a few Bitcoins to Jeff and updates the state channel within their channel.
  • Additionally, Joe sends a hint of the transaction to a watchtower to keep an eye on the transaction without disclosing its contents.
  • Moreover, Joe sends her signature to the watchtower to pre-authorize the channel funds, allowing it to be sent back in case of a channel breach.
  • The watchtower then cross-verifies the hints received from the client (Joe) and the Bitcoin blockchain.
  • If the watchtower identifies a channel breach by Jeff through an invalid state broadcast, a penalty transaction is created using Joe’s signature and finally reverses the channel funds back to him.

Hence, Joe is protected from a channel breach without having to be online as it was taken care of by the watchtowers.

Development and Challenges

The watchtower market is still in the development stage and is yet to be accepted in the mainstream as the lighting network is gradually inching into a more extensive P2P payment system using Bitcoin.

That said, researchers and enthusiasts believe that this field will provide a compelling future for LN watchtowers. We are uncertain how much-biased will users be towards using the watchtower services, but for the security assurances they provide, it is worth to be considered.

The service enabled by watchtowers would undoubtedly take away the abstract of complexity in components from the users, but considerable progress in both time and developments is vital when aiming for high-end features in the lighting network.

In conclusion, the fact that watchtowers present a prospective thinking approach to security risks imposed by the evolving Bitcoin indicates a sustainable ecosystem in the future.