Editing Identity-based encryption (section)

{{Short description|Type of public-key encryption}}
'''Identity-based encryption''' ('''IBE'''), is an  important primitive of [[identity-based cryptography]]. As such it is a type of [[public-key encryption]] in which the [[public key]] of a user is some unique information about the identity of the user (e.g. a user's email address).  This means that a sender who has access to the public parameters of the system can encrypt a message using e.g. the text-value of the receiver's name or email address as a key. The receiver obtains its decryption key from a central authority, which needs to be trusted as it generates secret keys for every user.

Identity-based encryption was proposed by [[Adi Shamir]] in 1984.<ref name="iseca.org">{{cite conference
 | last = Shamir | first = Adi | author-link = Adi Shamir
 | editor1-last = Blakley | editor1-first = G. R.
 | editor2-last = Chaum | editor2-first = David
 | contribution = Identity-Based Cryptosystems and Signature Schemes
 | doi = 10.1007/3-540-39568-7_5
 | pages = 47–53
 | publisher = Springer
 | series = Lecture Notes in Computer Science
 | title = Advances in Cryptology, Proceedings of CRYPTO '84, Santa Barbara, California, USA, August 19–22, 1984, Proceedings
 | volume = 196
 | year = 1984| doi-access = free
 }}</ref> He was however only able to give an instantiation of [[Identity-based cryptography|identity-based signatures]]. Identity-based encryption remained an open problem for many years.

The [[pairing-based cryptography|pairing]]-based [[Boneh–Franklin scheme]]<ref>{{cite journal
 | last1 = Boneh | first1 = Dan | author1-link = Dan Boneh
 | last2 = Franklin | first2 = Matthew | author2-link = Matthew K. Franklin
 | doi = 10.1137/S0097539701398521
 | issue = 3
 | journal = [[SIAM Journal on Computing]]
 | mr = 2001745
 | pages = 586–615
 | title = Identity-based encryption from the Weil pairing
 | volume = 32
 | year = 2003}}</ref> and [[Cocks IBE scheme|Cocks's encryption scheme]]<ref>{{cite conference
 | last = Cocks | first = Clifford C. | author-link = Clifford Cocks
 | editor-last = Honary | editor-first = Bahram
 | contribution = An identity based encryption scheme based on quadratic residues
 | doi = 10.1007/3-540-45325-3_32
 | pages = 360–363
 | publisher = Springer
 | series = Lecture Notes in Computer Science
 | title = Cryptography and Coding, 8th IMA International Conference, Cirencester, UK, December 17–19, 2001, Proceedings
 | volume = 2260
 | year = 2001}}</ref> based on [[quadratic residue]]s both solved the IBE problem in 2001.