  Currently, one of the most widely used protocols to secure cryptocurrency
assets in centralized exchanges is categorizing wallets into cold and hot.
While cold wallets hold user deposits, hot} wallets are responsible for
addressing withdrawal requests. However, this method has some shortcomings such
as: 1) availability of private keys in at least one cold device, and~2)
exposure of all private keys to one trusted cold wallet admin. To overcome such
issues, we design a new protocol for managing cold wallet assets by employing
native multi-signature schemes. The proposed cold wallet system, involves at
least two distinct devices and their corresponding admins for both wallet
creation and signature generation. The method ensures that no final private key
is stored on any device. To this end, no individual authority can spend from
exchange assets. Moreover, we provide details regarding practical
implementation of the proposed method and compare it against state-of-the-art.
Furthermore, we extend the application of the proposed method to an scalable
scenario where users are directly involved in wallet generation and signing
process of cold wallets in an MPC manner.
