Authentication ranks with identities based on elliptic curves
Nicolae Constantinescu · Annals of the University of Craiova Mathematics and Computer Science Series · 2007
The giving paper treats the way in which a symmetric cryptographic key, which has been acknowledged by the two counterparts on a communications network, is being created. It will be treated the manner in which the two will authentify their selfs, by using secret information and arbitrary strings, which can be the names of the two. On these strings other data that will be added, competing for the flnal deflnition of the key. It will also consider the case in when we can use the access information's hierarchy. In order to facilitate the assurance of confldentiality regarding the communication, the requirements imposed by the following three basic steps must be fulfllled. The steps are: (1) The making and distribution of a master key, (2) The agreement on a protocol which will create a session key, used by the com- municating parts for the current message session, (3) The encryption algorithm based on the participant's acknowledged key. The system is viable for the case in which we have an encryption, with a symmetric key, of the messages and an agreement on the session key which is based on public keys. The founding idea of the identities system belongs to Shamir (5) He wanted to create a method which will secure the e-mail. If Ann and Bob are two persons who want to communicate, each one has an e-mail address. When Ann wants to send a message to Bob, she will make a request to the server which holds Bob's public key and will encrypt the information with it. The server will manage both the public and the secret key of the participants at the dialog. The key request will be composed by sending the server a request which contains the e-mail address for whom the public key is wanted. The modiflcations introduced by Shamir consists of a function, ´, which generates a public key from an arbitrary string ( e-mail address). In this way Ann will not ask for the key from the server any more, she will encrypt messages using the key generated by function ´. The beneflts from this system is the fact of one can encrypt and send a message to another even if the Password Server is not available in that moment, and in this way the talk between Ann and the Server is not needed anymore. Throughout time, diverse algorithms which relay on this system as a base have been proposed, (4, 6), but not many of them can be put into practice because the implementations impose too heavy burden on the current calculus systems.