"Decentralize your own security," says Ethereum founder Vitalik Buterin—but he doesn't use a cold wallet for his own personal crypto. Ethereum founder Vitalik Buterin is advising people to "decentralize your own security," after weighing in on a Twitter discussion about using cold wallets. To prove his point, Buterin said that he keeps 90% of his crypto funds in a mutisig Safe wallet. "M-of-N, some keys held by you (but not enough to block recovery), the rest held by other people you trust," he wrote. "Don't reveal who those other people are, even to each other." The "m-of-n" Buterin referred to describes one of the ways multisig, or multi-signature, wallets can be set up. The first variable refers to minimum number of signatures required to sign a contract, therefore spending or transferring funds from the wallet. The second variable refers to the total number of possible signatories that exist for the wallet.