# Shared-Custodial Wallet for Multi-Party Crypto-Asset Management
## 7 Related Work  
Single-signature wallets, the most traditional form of digital asset custody, rely on a single private key for transaction authorisation. While widely adopted, these wallets have significant vulnerabilities. Loss or theft of the private key results in irrevocable loss of assets. Academic work such as [PERSON] et al. 's Pure Wallet [28] explored enhancements to single-signature wallets by incorporating offline transaction capabilities and smart contract support. However, these designs lack fraud detection and scalability mechanisms in high-demand environments. Similarly, [PERSON] et al. [29] examined cold wallet solutions but focused mainly on transaction security without addressing the issues of recovery or dynamic use cases. These shortcomings underscore the limitations of single-signature models in modern applications. To overcome the limitations of single-signature wallets, multi-signature wallets emerged as an alternative. Unlike single-signature wallets, multi-signature wallets distribute control across multiple parties, enhancing security by requiring multiple cryptographic signatures for transaction authorisation [8]. Despite these advancements, multi-signature wallets often increase transaction validation time and require blockchain protocol modifications or smart contract integrations [30]. Unlike multi-signature models, MPC wallets employ threshold cryptographic techniques to enable decentralised signing processes without revealing private keys to any single participant [11]. Threshold signature schemes offer superior efficiency by generating a single signature compatible with existing blockchain protocols, avoiding the need for protocol modifications required by multi-signature wallets [10]. [PERSON] et al. [31] highlighted the promise of MPC for balancing security and usability in custodial applications. Notable advancements in this area include [PERSON]'s two-party threshold EllipticCurve Digital Signature Algorithm (ECDSA) protocol [32], which leverages conventional Paillier encryption, and [PERSON] et al. 's extension to t-out-of-n threshold settings [33], employing [PERSON]'s secret sharing to enhance flexibility and security. In blockchain ecosystems, [PERSON] et al. [34] advanced MPC-based ECDSA protocols for cold storage, reducing attack vectors by leveraging non-interactive pre-signing modes. More recently, [PERSON] et al. [30] integrated MPC with Bloom filters to enhance transaction validation and participant privacy. However, these studies often focus on generic key management use cases and do not elaborate on the key recovery mechanism. Diverse key management approaches also exist in the industry, showcasing a landscape of major institutional custody providers (see Table 1). These approaches include hardware security modules (HSMs), specialised hardware devices that securely generate, store, and process cryptographic keys while protecting against tampering [35]. This diversity highlights the range of available solutions in key management techniques, blockchain support, and compliance measures. Our design addresses academic gaps and builds upon these industry observations by proposing a blockchain-agnostic MPC-TSS wallet tailored for wealth managers, combining decentralised key management, securely distributed recovery, and efficient transaction management.