Page 115 - DCAP309_INFORMATION_SECURITY_AND_PRIVACY

Unit 8: Cryptography and Encryption

Electronic credentials are intended to permit the credence of a claim to be confirmed Notes
electronically. Even though no purely electronic credentialing systems are in widespread use at
this time, many such systems are being incorporated into the smart-card systems in widespread
use in Europe. A smart-card is just a credit-card shaped computer that performs cryptographic
functions and accumulates secret information. When used in combination with other devices
and systems, it permits a broad variety of cryptographic applications to be performed with
relative ease of use to the customer.

8.2.7 Electronic Signatures

Electronic signatures are a means of supplying a lawfully binding transaction between two or
more parties. To be as functional as a physical signature, electronic signatures must be at least as
hard to fake at least as easy to use, and accepted in a court of law as binding upon all parties to
the operation.

The requirement for these electronic signatures is particularly acute in business dealings wherein
the parties to a agreement are not in the same physical vicinity.

Example: An global sale of an airplane, signatures are usually required from two bankers,
two companies, two insurance agencies, two attorneys, two governments, and frequently several
other parties.
The contracts are hundreds of pages long, and signatures must be achieved within a relatively
short phase of time on the similar physical document. Faxcimily signatures are not lawfully
binding in all jurisdictions, and the sheer length of a document prevents all parties reading the
present copy as they meet at the table to affix signatures. Under current law, all parties must
meet in one location so as to complete the transaction. In a transatlantic sale, $100,000 in costs can
simply be incurred in such a meeting.
An attempt in Europe is at present underway to restore physical signatures with electronic
signatures based on the RSA cryptosystem. If this effort succeeds, it will permit many millions
of dollars to be saved, and launch the period of digital signatures into full scale motion. It will
also make a large savings for those who use the system, and thus act to force others to participate
in order to remain competitive.

8.2.8 Electronic Cash

There are patents under force throughout the world today to allow electronic information to
replace cash money for financial transactions between individuals. Such a system involves
using cryptography to keep the assets of nations in electronic form. Clearly the ability to forge
such a system would allow national economies to be destroyed in an instant. The pressure for
integrity in such a system is staggering.

8.2.9 Threshold Systems

Thresholding systems are systems intended to permit use only if a minimal number of parties
consent to the said use.

Example: In a nuclear arms circumstances, you might want a system in which three out
of five members of the joint chiefs of staff have the same opinion. In a banking situation, a safe
might only be opened if 4 out of the certified 23 people permitted to open the safe were present.
Such systems prevent a single individual acting alone, while permitting many of the parties to
a transaction to be missing without the transaction being halted.

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