Workflow of a zkSync Era transaction: from generation to finalization

This blog post presents the entire workflow of a transaction executed on zkSync Era. zkSync Era is a Zk Rollup Layer 2 blockchain that executes transactions and proves its execution on the Ethereum blockchain using Zero-Knowledge proofs.

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A Brief Overview of Auditing XCMv2

Parity Tech mandated Quarkslab to audit XCM version 2 (XCMv2), a cross consensus communication mechanism. This messaging protocol is a cornerstone of the Polkadot ecosystem as it enables communications between chains on a network. This blog post summarizes few security aspects related to this technology and its implementation. The full audit report is available in PDF format at the end of this article.

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Technical Assessment of the herumi Libraries

The Ethereum Foundation mandated Quarkslab to perform an audit of the herumi libraries. They provide an API to perform BLS signatures, one of the core components of the new iteration of the Ethereum blockchain, named Ethereum 2.0. While reviewing the architecture of these libraries, their back ends and the adherence with the ongoing RFCs to standardize BLS signature usage, we found some issues primarily regarding their design. Although these are not considered critical, they impact the overall reliability of the libraries. We provide recommendations to improve the design of the libraries, the readability of the code and the usability of both projects.

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Security Audit of dalek libraries

The Tari Labs mandated Quarkslab to perform a cryptographic and security assessment of the dalek libraries. One of the Tari Labs' projects is to implement the Tari protocol, a decentralised assets protocol. It relies on some of the dalek libraries, especially the cryptographic primitives, provided by subtle and curve25519-dalek. Moreover, the use of Bulletproofs [6], and its implementation by the authors of the dalek libraries, will allow them to enable efficient confidential transactions on the blockchain in a near future.

We only found some minor issues. We also provided recommendations on the usage of the libraries and third-party libraries.

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Security Audit of Monero RandomX

Quarkslab's team performed a cryptographic and security assessment of the Monero Research Lab’s new Proof-of-Work algorithm, called RandomX [1]. RandomX is a proof-of-work algorithm that is optimized for general-purpose CPUs. RandomX uses random code execution together with several memory-hard techniques to minimize the efficiency advantage of specialized hardware. We only found minor inconsistencies and formulated a few recommendations. These recommendations are mainly relevant when using alternative configurations but they are of less importance with the current configuration and usage of RandomX. The full report of the assessment can be found at the following address: [2]

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Security Audit of Particl Bulletproof and MLSAG

Quarkslab's team performed a cryptographic and security assessment of both the Bulletproof and MLSAG protocols in Particl. Bulletproof is a non-interactive zero-knowledge proof protocol, while MLSAG is a new ring signature protocol. Both are to be used in cryptocurrency transactions to ensure that they do not leak the amount exchanged or the exact identity of the buyers. Both implementations were found sound and conform to their respective reference papers [BBBPWM18] [SN15]. The full report of the assessment can be found at the following address: [2]

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