RSA is the most widely used public-key cryptosystem today and has often
been called a de facto standard. Regardless of the official standards,
the existence of a de facto standard is extremely important for the
development of a digital economy. If one public-key system is used
everywhere for authentication, then signed digital documents can be
exchanged between users in different nations using different software
on different platforms; this interoperability is necessary for a true
digital economy to develop.
The lack of secure authentication has been a major obstacle in achieving the promise that computers would replace paper; paper is still necessary almost everywhere for contracts, checks, official letters, legal documents, and identification. With this core of necessary paper transaction, it has not been feasible to evolve completely into a society based on electronic transactions. Digital signatures are the exact tool necessary to convert the most essential paper-based documents to digital electronic media. Digital signatures makes it possible, for example, to have leases, wills, passports, college transcripts, checks, and voter registration forms that exist only in electronic form; any paper version would just be a ``copy'' of the electronic original. All of this is enabled by an accepted standard for digital signatures.