Blockchains, in general, and cryptocurrencies such as Bitcoin, in particular, are realized
using distributed systems and hence critically rely on the performance and security of the …

Proof-of-work puzzles and CAPTCHAS consume enormous amounts of energy and time.
These techniques are examples of resource burning: verifiable consumption of resources …

Blockchains use peer-to-peer networks for disseminating information among peers, but
these networks currently do not have any provable guarantees for desirable properties such …

A Sybil attack occurs when an adversary controls multiple system identifiers (IDs). Limiting
the number of Sybil (bad) IDs to a minority is critical for tolerating malicious behavior. A …

Cryptocurrencies such as Bitcoin are realized using distributed systems and hence critically
rely on the performance and security of the interconnecting network. The requirements on …

Proof-of-Stake cryptocurrencies avoid many of the computational and environmental costs
associated with Proof-of-Work protocols. However, they must address the nothing-at-stake …

Blockchains have become ubiquitous in the world of robust decentralized applications. A
crucial requirement for implementing a blockchain is a reliable “overlay network” providing …

Proof-of-stake cryptocurrencies avoid many of the computational and environmental costs
associated with proof-of-work protocols. However, they must address the nothing-at-stake …

Fast data dissemination in blockchain networks refers to the efficient and timely data
propagation across nodes. Each node stores a copy of the blockchain ledger and uses …

Abstract In 1993, Dwork and Naor proposed using computational puzzles, a resource
burning mechanism, to combat spam email. In the ensuing three decades, resource burning …