Swiss digital asset bank Sygnum has unveiled a Bitcoin-backed lending solution that allows borrowers to retain custody of their private keys while accessing fiat credit. The product, developed in partnership with blockchain platform Debifi, uses a three-of-five multisignature custody model to prevent third-party collateral reuse. The platform, branded MultiSYG, is scheduled for early 2026 release and targets institutional clients seeking liquidity without surrendering asset control.