The European Union Electronic Signature Directive of January, 2000, defines an advanced electronic
signature. This signature must meet all of the following requirements except that:
A.
It must be created using means that are generally accessible and available.
B.
It must be uniquely linked to the signatory.
C.
It must be linked to the data to which it relates in such a manner that any subsequent change of
the data is detectable.
D.
It must be capable of identifying the signatory.
Explanation:
The Directive requires that the means be maintained under the sole control of the signatory. This
requirement is a particularly difficult one to achieve. One approach is to use different tokens or
smart cards for the different transactions involved. The other answers are typical characteristics of
digital signatures that can be implemented with public key cryptography.