A one-time memory (OTM) stores two bits such that either bit can be retrieved, but not both. One-time memories have been shown to allow for secure classical and quantum computations. We propose a physical construction of this mathematical cryptographic primitive, based on isolated Majorana islands. Using classical error-correcting codes, obtained from a quantum code, the scheme can be made robust to errors. Further, the one bit out of two bit OTM construction generalizes to 1-out-of-n and (n − 1)-out-of-n OTMs.