Digital Garage Group


Aug 08, 2022

A paper on the practical improvements of Discreet Log Contracts co-authored by two researchers at Crypto Garage was accepted to the top level “IEEE International Conference on Blockchain and Cryptocurrency 2022”.

Researchers at Crypto Garage, Inc. (headquartered in Tokyo, Shibuya-ku, President and CEO: Okuma Masahito, further referred as Crypto Garage) submitted a paper to one of the top level IEEE conference in the domain of blockchain, the “IEEE International Conference on Blockchain and Cryptocurrency (ICBC) 2022”. The paper was accepted for presentation and publication.

The paper is based on the concept of Discreet Log Contracts (DLC), proposed by Tadge Dryja in 2017, a researcher at the MIT Digital Currency Initiative, which enables the establishment of derivatives and other types of contracts on the Bitcoin blockchain. The paper proposes practical improvements over this seminal work, in particular:

– The use of “adaptor signatures” that increase on-chain privacy of the contract and removes the need for interaction between parties after contract setup,
– Numerical decomposition of outcomes for contracts based on numerical values, which improves contract setup time as well as storage and communication overhead,
– Enable the use of multiple oracle for a single contract, reducing the reliance on a single point of failure, while preserving the ability to generate fraud proofs and hold misbehaving oracle accountable,
– Several algorithmic optimizations to reduce contract setup time, such as “pre-computation of anticipation points”, “memoization” and “parallelization of anticipation points and signatures computations”,
– Performance experiments evaluating the improvements provided by the various optimizations as well as the overall setup time of a complex DLC.

The research presented in the paper is the result of joint research between Crypto Garage and Suredbits (headquartered in San Mateo, California, representative director: Chris Stewart), and was presented at the ICBC 2022 conference held between the 2nd and 5th May 2022. The content of the paper is based on an ongoing specification effort conducted with several other companies and independent researchers around the world. Crypto Garage continues to take an active part in this effort as well as contributing to the implementation of the specifications.

– Link to the published paper:
Bitcoin Oracle Contracts: Discreet Log Contracts in Practice

– Repository of the DLC specifications:

– DLC library implemented by Crypto Garage:

Crypto Garage has provided blockchain settlement services and related products, such as “SETTLENET,” to Japanese and global crypto asset business operators. In June 2021, Crypto Garage completed the registration as a crypto asset exchange service provider under the Payment Services Act at the Kanto Local Finance Bureau, and is allowed to provide brokerage services between Japanese crypto asset exchanges and liquidity providers.Crypto Garage will continue contributing to the development of the cryptocurrency and blockchain eco-systems and further develop advanced financial services in these domains.

If you have any questions or have interest in the products and services offered by Crypto Garage, please contact