distributed_keygen.paillier_shared_key module
Paillier secret key that is shared amongst several parties.
- class distributed_keygen.paillier_shared_key.PaillierSharedKey(n, t, player_id, share, theta)[source]
Bases:
SecretKey
Class containing relevant attributes and methods of a shared paillier key.
- __init__(n, t, player_id, share, theta)[source]
Initializes a Paillier shared key.
- Parameters:
n (
int
) – modulus of the DistributedPaillier scheme this secret key belongs tot (
int
) – corruption_threshold of the secret sharingplayer_id (
int
) – the index of the player to whom the key belongsshare (
IntegerShares
) – secret sharing of the exponent used during decryptiontheta (
int
) – Value used in the computation of a full decryption after partial decryptions have been obtained. We refer to the paper for more details
- __str__()[source]
Utility function to represent the local share of the private key as a string.
- Return type:
str
- Returns:
String representation of this private key part.
- decrypt(partial_dict)[source]
Function that uses partial decryptions of other parties to reconstruct a full decryption of the initial ciphertext.
- Parameters:
partial_dict (
Dict
[int
,int
]) – dictionary containing the partial decryptions of each party- Raises:
ValueError – Either in case not enough shares are known in order to decrypt. Or when the combined decryption minus one is not divisible by \(N\). This last case is most likely caused by the fact the ciphertext that is being decrypted, differs between parties.
- Return type:
int
- Returns:
full decryption
- partial_decrypt(ciphertext)[source]
Function that does local computations to get a partial decryption of a ciphertext.
- Parameters:
ciphertext (
PaillierCiphertext
) – ciphertext to be partially decrypted- Raises:
TypeError – If the given ciphertext is not of type PaillierCiphertext.
ValueError – If the ciphertext is encrypted against a different key.
- Return type:
int
- Returns:
partial decryption of ciphertext