Identity-based encryption

Identity-based encryption (IBE), is an important primitive of <a href="/facts/Identity-based_cryptography/kssqdqmg">identity-based cryptography</a>. As such it is a type of <a href="/facts/Public-key_encryption/gowoFTxS">public-key encryption</a> in which the <a href="/facts/Public_key/gowoFTxS">public key</a> 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 <a href="/facts/Adi_Shamir/CTnaUeP6">Adi Shamir</a> in 1984. He was however only able to give an instantiation of <a href="/facts/Identity-based_cryptography/kssqdqmg">identity-based signatures</a>. Identity-based encryption remained an open problem for many years.
The <a href="/facts/Pairing-based_cryptography/vpk8ygca">pairing</a>-based <a href="/facts/Boneh%25E2%2580%2593Franklin_scheme/P3tdw7Rq">Boneh–Franklin scheme</a> and <a href="/facts/Cocks_IBE_scheme/CzweqJlE">Cocks's encryption scheme</a> based on <a href="/facts/Quadratic_residue/rHD2uQdQ">quadratic residues</a> both solved the IBE problem in 2001.

Identity-based encryption open-in-new

Identity-based encryption