Cryptosat and Protocol Labs Collaborate to Take Cryptography to Space

Yan Michalevsky
Published in
5 min readMar 1, 2022


(original publication at

Palo Alto, California (December 21, 2021)Cryptosat, a team of Stanford University PhDs and alumni who build satellites that power cryptographic, blockchain and ledger applications, and Protocol Labs, an open-source R&D lab that builds protocols, tools, and services to radically improve the internet (including Filecoin and IPFS), announced their collaboration to bring the new cryptographic primitive Verifiable Delay Function (VDFs) technology to space. The collaboration also includes the work of researchers Bernardo David (IT University of Copenhagen) and Carsten Baum (Aarhus University).

As part of this project, Cryptosat, Protocol Labs, David, and Baum will experiment with how the physical properties of communication with satellites can benefit time-based cryptographic primitive designs, and provide lower bounds on the delay guaranteed by such constructions. Time-based cryptographic primitives such as Verifiable Delay Functions (VDFs) provide functionality that is difficult or impossible to get in other ways in fully decentralized systems, including unbiasable/unstoppable randomness and a proxy for passage of time. Privacy and scalability are two of the main concerns that prevent the broader use of blockchain in many end-user applications. Time-based primitives have the potential to improve the security, privacy, and scalability of blockchain platforms.

Speaking about the launch of the new enterprise, Yonatan Winetraub, a Co-Founder of Cryptosat and Co-Founder of SpaceIL (which launched the first private mission to the moon in 2019), said, “Cryptosat’s mission is to utilize unique satellite properties to power cryptographic, blockchain, and ledger applications. By launching these platforms into space, we aim to unlock new and exciting opportunities in the realm of computing, and guarantee ultimate trust and transparency, ranging from blockchain to securing Internet transactions. We are very excited to be working with Protocol Labs on this historic enterprise and believe it will help us bring about a world with a more secure internet.”

In this project, time-based primitives using communication delays will be constructed following a first principles approach using the paradigm of provable security. As a first step, mathematical models capturing the properties of communication delays and the security guarantees expected from such time-based primitives will be created. Later on, constructions of VDFs and Time-Lock Encryption will be proven to achieve the required security guarantees according to these models. Moreover, new protocols for randomness generation specially fit to the setting of communication delays will be investigated. Finally, auxiliary protocols will be developed for eliminating the trust in the satellites, guaranteeing that a minimal delay is guaranteed even if a number of satellites are compromised.

Professor Bernardo David, said, “The goal of this project is to construct time-based primitives whose delay guarantees come from communication rather than computation. Einstein’s special relativity theory established that the communication delay between two devices is at least as much time as light takes to travel from one device to the other. This fundamental limit is well understood and does not depend on our understanding of algorithms for solving sequential problems nor on the availability of faster hardware and more computational resources. Hence, by constructing time-based primitives from communication delays, it is possible to provide a clear concrete guarantee about the minimal delay provided by such primitives. However, since the speed of light is quite high, communication delays only become apparent over very long distances. This is exactly why there is an advantage in relying on communication delays between earth and satellites rather than between two points located on earth.”

Cryptosat and Protocol Labs intend to address the challenges of securing computing devices by placing a secure compute platform on a network of satellites in space. While on Earth, computing devices are vulnerable to hacking and physical attacks, placing the network into space orbit would place it beyond anyone’s physical reach. In time, this network of satellites might even take the place of blockchain mining by providing a wholly trusted, tamper-proof validator in space. This novel technology also has the long-term potential to allow for blockchain applications that are cheaper, more reliable, more efficient, and more secure. Additionally, the collaboration hopes to provide unique value for randomness generation, an area that is critical to the correct operations of many applications in cryptography. Generating random numbers is very important for cryptographic protocols such as the encryption that underlies the way the Internet works.

“One way to think about what we are trying to do is to think of a vault. If you have valuable items that you want to protect from a thief, you can put a vault in your home. If you can send that vault into space, you can be even more certain that no thieves will be able to steal your valuables, giving you out-of-this-world security,” said Cryptosat Co-Founder Yan Michalevsky. He added, “The inability to physically hack satellites guarantees that all communication will happen in the open, and that can create entirely new application possibilities here on Earth.”

Cryptosat, established in 2020, is the brainchild of three Stanford University graduates: Winetraub; Yan Michalevsky, Chief Technology Officer of Anjuna Security; and Gil Shotan, an engineer who previously worked with Google X and the moonshot factory, and who, for the past few years, has been working on autonomous vehicles as part of Waymo, Google’s self-driving car program. Protocol Labs is an open-source R&D lab that builds protocols, tools, and services to radically improve the internet. Protocol Labs’ projects include IPFS, Filecoin, libp2p, and more — which serve thousands of organizations and millions of people. Protocol Labs is currently working with the Ethereum Foundation, the Filecoin Foundation, Supranational, Microsoft Research, and the Electric Coin Company on improving the performance of SNARKs and to produce a practical SNARK-based VDF design and implementation.

Chhi’mèd Künzang, Project Lead at Protocol Labs, says, “Verifiable delay functions based on communication latency, rather than computational performance, are exciting because they allow us to minimize Amax (Attacker’s Maximum Advantage). Not only does this make the resulting primitives more efficient, it opens the door for protocols requiring precise timing guarantees. For example, there are proposed Filecoin enhancements which will only be feasible if such VDFs are realized in practice.”