Module ibe::kem::cgw_fo

Available on crate feature cgwfo only.

IND-ID-CCA2 secure IBKEM by a scheme by Chen, Gay and Wee.

• From: “Improved Dual System ABE in Prime-Order Groups via Predicate Encodings”

CCA security due to a general approach by Fujisaki and Okamoto.

• From: “A Modular Analysis of the Fujisaki-Okamoto Transformation”

Symmetric primitives G and H instantiated using sha3_512 and sha3_256, respectively. To output a bigger secret SHAKE256 can be used with a bigger output buffer.

A drawback of a Fujisaki-Okamoto transform is that we now need the public key to decapsulate.

Re-exports

• pub use crate::ibe::cgw::PublicKey;
• pub use crate::ibe::cgw::SecretKey;
• pub use crate::ibe::cgw::CT_BYTES;
• pub use crate::ibe::cgw::MSG_BYTES;
• pub use crate::ibe::cgw::PK_BYTES;
• pub use crate::ibe::cgw::SK_BYTES;

Structs

• CGWFO
  The CCA2 secure KEM that results by applying the implicit rejection variant of the Fujisaki-Okamoto transform to the Chen-Gay-Wee IBE scheme.
• UserSecretKey
  User secret key. Can be used to decaps the corresponding ciphertext. Also known as USK_{id}.

Constants

• USK_BYTES
  Size of the compressed user secret key in bytes.