<Dt> Users (and their software) must carry out the signature protocol properly . </Dt> <Li> <Dl> <Dt> The private key must remain private </Dt> <Dd> If the private key becomes known to any other party, that party can produce perfect digital signatures of anything whatsoever . </Dd> </Dl> </Li> <Dl> <Dt> The private key must remain private </Dt> <Dd> If the private key becomes known to any other party, that party can produce perfect digital signatures of anything whatsoever . </Dd> </Dl> <Dt> The private key must remain private </Dt>

What is the most obvious means of providing non-repudiation