Crate confium_tc_ecies_p256 

Threshold ECIES over P-256 — real implementation.

ECIES (Elliptic Curve Integrated Encryption Scheme) on P-256:

• Encryptor generates ephemeral scalar r, computes R = r * G
• Encryptor computes ECDH shared secret K = r * recipient_pubkey
• Encryptor derives AEAD key from K via HKDF-SHA256
• Encryptor encrypts plaintext with AES-256-GCM
• Output: (R, ciphertext, nonce, tag)

Threshold variant: recipient’s private scalar x is Shamir-shared among N parties. Each party computes partial_i = x_i * R. Combined via Lagrange: sum_i λ_i * partial_i = x * R = K. From K, the AEAD key is derived and decryption proceeds normally.

Used for browser-side key escrow and Mode 2 enterprise secrets.

See TODO.roadmap/31-threshold-encryption.md for full spec.

Re-exports

pub use keys::generate_keypair;

pub use shamir::Share;

pub use shamir::recover_secret;

pub use shamir::split_secret;

Modules

keys

Keypair generation for threshold ECIES-P256.

shamir

Real Shamir secret sharing over the P-256 scalar field.

Structs

DecryptionShare

Share of the threshold ECIES secret key.

EncryptedBlob

ECIES-encrypted blob.

PartialDecryption

Partial decryption from one party: share * R as SEC1 bytes.

PublicKey

Threshold ECIES public key.

Enums

EciesError

Errors during threshold ECIES operations.

Constants

ALGORITHM

Algorithm identifier.

Functions

aggregate_partials

Aggregate T partial decryptions to recover the plaintext.

encrypt

Encrypt plaintext to recipient using ECIES-P256 + AES-256-GCM.

partial_decrypt

Compute a partial decryption: share * R where R is the blob’s ephemeral public key.