- Two foundational papers on “verifiable partial key escrow” were shared: the 1997 IBM Research Report “Verifiable Partial Key Escrow” and the 1998 ACM Conference version “Publicly Verifiable Partial Key Escrow,” both proposing cryptographic schemes that let users escrow only part of a private key while allowing third-party verification that the remaining portion can be reconstructed under lawful warrant—an early exploration of balancing strong encryption with government access demands.