41 course, to the validity or value of the information in a document. Both studies and common sense indicate, however, that the full potential of ecommerce will not develop until there is a sufficiently trusted means of communicating and authenticating communications—of performing functions similar to those of signatures. In an electronic environment, the original of a message cannot be distinguished from a copy; there is no handwritten signature; it is not on paper; and it can be manipulated or altered without being easily discernable—indeed, it can be altered without the direct intervention of a human. There is considerable scope for fraud or error. The purpose of electronic signatures is to offer some technical means by which the characteristics of a signature can be duplicated in an electronic environment. 6.3.2 Depending on the importance of the document, electronic signatures may be a necessary and inherent part of the communication under ecommerce or electronic transactions statutes. Phrases such as “secure electronic signatures” may not only satisfy provisions relating to signatures, but also with legislative language dealing with witnesses, notarisation, and statements made under oath. They may also be used to deal with requirements for “original” documents. 6.3.3 Cryptography can also provide technical solutions for protection of intellectual property in digital form. For example, a digital signature in conjunction with a verifiable time stamp can give authors some control over their work by tying an electronic document to a particular issuer and ensuring that it cannot be altered without detection. This technology can also be used to ensure the integrity of electronic archives, an increasingly important issue. 6.3.4 Virtually all OECD countries have some form of legislative or regulatory framework in place to provide for the legal effect of electronic signatures. While details differ, there is a consistent approach. All are theoretically technology neutral, although in some cases where a high degree of certainty was required, policies specified the use of technology that was asymmetric cryptography-based. 6.3.5 Digital signatures are an important application of public key cryptography, which must be considered in conjunction with policy development on cryptography, discussed above.35 Other authentication models are possible, including biometric devices, use of personal identification numbers (PINS) or “passwords,” digitised versions of 35 Using cryptography for digital signatures should not be confused with the creation of confidential messages, which may be limited in some circumstances (or using some methodologies) for reasons of national security or defence. Digital signatures using cryptography may be appended to non-encrypted messages.