In 1976, Whitfield Diffie and Martin Hellman published a cryptographic protocol, (Diffie-Hellman key exchange), which allows users to establish secure channels in order to exchange keys, even if an attacker is monitoring that communication channel. However, Diffie-Hellman key exchange did not address the "identity authentication" problem of being sure of the actual identity of the person or an entity.
Public key infrastructures have been proposed go around the problem of "identity authentication". In their most usual implementation, each user applies to a "certificate authority" for a digital certificate which serves for other users as a correct (termed: non-tamperable) authentication of identity.
In contrast, the web of trust system, which do not use central "certificate authority" at all. Each user is responsible for verifying any certificate from another user before using that certificate to communicate with the user who claims to be associated with the particular public key in a certificate, (see digital signatures).
The problem of key exchange has not yet been solved. In particular, it has not yet been solved for the modern situation of two previously unknown users attempting to communicate electronically, as, for instance, in electronic commerce. Some of the existing work-around designs work, more or less, but are not fully satisfactory.
Secure channel
In cryptography, a secure channel is a way of transferring data that is very difficult (called r"esistant") to overhear or copy (called "interception") and understand (called "decrypt") or change (called "tampering").
A confidential channel is a way of transferring data that is resistant to interception, but may not be resistant to tampering and may not be resistant to impersonation by someone else (called "spoofing").
An authenticatable channel is a way of transferring data that is resistant to spoofing but may not be resistant to interception or tampering.
Terminology
Terminology is the study of terms and their use. Terminology studies the "labelling or designating of concepts" in one or more subject fields or areas of human activity. Terms are words and compound words that are used in specific contexts. Terminology studies among other things how such terms of art come to be and their interrelationships within a culture.
Work on terminology consists mainly of:
Communes of the Vaucluse department
There are 261 communes in the Vaucluse department in France, all included in the following list:
Althen-des-Paluds
Althen-des-Paluds is a commune of 1988 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Ansouis
Ansouis is a commune of 1,105 people (2006). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Apt, Vaucluse
Apt is a commune of 11,229 people (2006). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Aubignan
Aubignan is a commune of 3,877 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Aurel, Vaucluse
Aurel is a commune of 158 people (2008). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Auribeau
Auribeau is a commune of 59 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Le Barroux
Le Barroux is a commune of 615 people (2006). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
La Bastide-des-Jourdans
La Bastide-des-Jourdans is a commune of 964 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
La Bastidonne
La Bastidonne is a commune of 677 people (1999). It is found in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Le Beaucet
Le Beaucet is a commune of 352 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Beaumes-de-Venise
Beaumes-de-Venise is a commune of 2,070 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Beaumettes
Beaumettes is a commune of 197 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Beaumont-de-Pertuis
Beaumont-de-Pertuis is a commune of 934 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Beaumont-du-Ventoux
Beaumont-du-Ventoux is a commune of 286 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Bédarrides
Bédarrides is a commune of 5,110 people (as of 1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Bédoin
Bédoin is a commune of 2,609 people (as of 1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Blauvac
Blauvac is a commune of 337 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Bollène
Bollène is a commune of 13,835 people (2006). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Bonnieux
Bonnieux is a commune of 1,417 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Brantes
Brantes is a commune of 65 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Buisson
Buisson is a commune of 264 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Buoux
Buoux is a commune of 112 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Cabrières-d'Aigues
Cabrières-d'Aigues is a commune of 819 people (2006). It is in the Provence-Alpes-Côte d'Azur region in the Vaucluse department in south France.
Cabrières-d'Avignon
Cabrières-d'Avignon is a commune of 1,705 people (2006). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Flag of Oman
The national flag of Oman () has three stripes (white, green and red) with a red bar on the left that contains the national emblem of Oman. The white stands for peace and prosperity, the green for fertility and the Green Mountains, and the red for battles against foreign invaders. The red is also the colour of the former flag of the nation when it was known simply as the Sultanate of Muscat and Oman.
Until 1970, Oman used the plain red banner of the indigenous people, the Kharijite Muslims. In 1970, the Sultan introduced a complete new set of national flags. Bands of green and white were added to the fly, and the national emblem, the badge of the Albusaidi Dynasty, was placed in the canton. This shows crossed swords over a Gambia, a traditional curved dagger. White has been associated historically with the Imam, the religious leader of Oman and at times the political rival to the ruling Sultan. It also symbolizes peace. Green is traditionally associated with the Jebel al Akhdar, or "Green Mountains," which lie toward the north of the country. Red is a common color in Gulf state flags. The national emblem is said to date back to the 18th century. A curved dagger is fastened over a pair of crossed swords. An ornate horsebit links the weapons.
Cadenet
Cadenet is a commune of 3,950 people (2006). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Caderousse
Caderousse is a commune of 2,496 people (1999). It is in the region Provence-Alpes-Côte d'Azur in the Vaucluse department in the south of France.
Coat of arms of Oman