templates.encryption_scheme module

Generic classes used for creating an encryption scheme.

class templates.encryption_scheme.Ciphertext(raw_value, scheme, **_kwargs)

Bases: Generic[CV]

Ciphertext objects support addition and multiplication by plaintext scalars.

abstractmethod __eq__(other)

Method that determines whether two Ciphertexts are the same.

Parameters:

other (object) – Ciphertext to be compared to Self.

Return type:

bool

Returns:

Boolean indicating whether they are the same.

__init__(raw_value, scheme, **_kwargs)

Constructs a Ciphertext with the given ciphertext value encrypted using the specified scheme.

Parameters:

• raw_value (TypeVar(CV)) – value of the ciphertext

• scheme (EncryptionScheme[Any, Any, Any, Self]) – encryption scheme used for creating this ciphertext

• **_kwargs (Any) – Optional extra keyword arguments for the constructor.

__str__()

Return type:

str

Returns:

String representation of Ciphertext.

scheme: EncryptionScheme[Any, Any, Any, Self]

property value: CV

Raw value of the ciphertext.

Returns:

Value of the ciphertext.

class templates.encryption_scheme.EncodedPlaintext(value, scheme)

Bases: Generic[RP]

Class that contains the encoding of a plaintext for a particular scheme.

Constructs an EncodedPlaintext with the given value and encoding as specified in the scheme.

Parameters:

• value (TypeVar(RP)) – value of the plaintext after encoding

• scheme (EncryptionScheme[Any, Any, TypeVar(RP), Any]) – encryption scheme that specifies the used encoding

Raises:

TypeError – provided scheme has the incorrect type.

__post_init__()

Validate encryption scheme.

Raises:

TypeError – Scheme is of the wrong type.

Return type:

None

scheme: EncryptionScheme[Any, Any, TypeVar(RP), Any]

value: TypeVar(RP)

class templates.encryption_scheme.EncryptionScheme(*_args, **_kwargs)

Bases: InstanceManagerMixin, ABC, Generic[KM, PT, RP, CT]

Abstract base class to define generic Homomorphic Encryption Scheme functionality. Can be used for all kinds of encryption schemes.

Most easily constructed using the from_security_parameter method.

abstractmethod __eq__(other)

Method that determines whether two EncryptionSchemes are the same.

Parameters:

other (object) – EncryptionScheme to be compared to Self.

Return type:

bool

Returns:

Boolean indicating whether they are the same.

__init__(*_args, **_kwargs)

Construct a new EncryptionScheme.

Parameters:

• *_args (Any) – Optional extra arguments for the constructor of a concrete implementation.

• **_kwargs (Any) – Optional extra keyword arguments for the constructor of a concrete implementation.

abstractmethod decode(encoded_plaintext)

Decode an EncodedPlaintext using the specified encoding scheme.

Parameters:

encoded_plaintext (EncodedPlaintext[TypeVar(RP)]) – Plaintext to be decoded.

Return type:

TypeVar(PT)

Returns:

Decoded Plaintext value

decrypt(ciphertext, apply_encoding=True)

Decrypts the input ciphertext.

Parameters:

• ciphertext (TypeVar(CT, bound= Ciphertext[Any])) – Ciphertext to be decrypted.

• apply_encoding (bool) – Boolean indicating whether the decrypted ciphertext is decoded before it is returned.

Return type:

TypeVar(PT)

Returns:

Plaintext decrypted value.

decrypt_sequence(ciphertext_sequence, apply_encoding=True)

Decrypts the list of input ciphertext.

Parameters:

• ciphertext_sequence (Iterable[TypeVar(CT, bound= Ciphertext[Any])]) – Sequence of Ciphertext to be decrypted.

• apply_encoding (bool) – Boolean indicating whether the decrypted ciphertext is decoded before it is returned.

Return type:

Iterator[TypeVar(PT)]

Returns:

A list of Plaintext decrypted values.

abstractmethod encode(plaintext)

Encode a supported Plaintext using the specified encoding scheme.

Parameters:

plaintext (TypeVar(PT)) – Plaintext to be encoded.

Return type:

EncodedPlaintext[TypeVar(RP)]

Returns:

EncodedPlaintext object containing the encoded value.

encrypt(plaintext, apply_encoding=True)

Encrypts the entered (encoded) Plaintext. Also encodes the Plaintext when this is required.

Parameters:

• plaintext (Union[TypeVar(PT), EncodedPlaintext[TypeVar(RP)]]) – Plaintext or EncodedPlaintext to be encrypted.

• apply_encoding (bool) – Boolean indicating whether a non-encoded plaintext should be encoded. If False, the plaintext is encrypted in raw form.

Return type:

TypeVar(CT, bound= Ciphertext[Any])

Returns:

Ciphertext object containing the encrypted value of the plaintext.

encrypt_sequence(plaintext_sequence, apply_encoding=True)

Encrypts the entered sequence of (encoded) Plaintext. Also encodes a Plaintext when this is required.

Parameters:

• plaintext_sequence (Iterable[TypeVar(PT)] | Iterable[EncodedPlaintext[TypeVar(RP)]]) – Sequence of Plaintext or EncodedPlaintext to be encrypted.

• apply_encoding (bool) – Boolean indicating whether a non-encoded plaintext should be encoded. If False, the plaintext is encrypted in raw form.

Return type:

Iterator[TypeVar(CT, bound= Ciphertext[Any])]

Returns:

Ciphertext object containing the encrypted value of the plaintext.

abstractmethod classmethod from_security_parameter(*args, **kwargs)

Generate a new EncryptionScheme from a security parameter.

Parameters:

• *args (Any) – Security parameter(s) and optional extra arguments for the EncryptionScheme constructor.

• **kwargs (Any) – Security parameter(s) and optional extra arguments for the EncryptionScheme constructor.

Return type:

Self

Returns:

A new EncryptionScheme.

abstractmethod static generate_key_material(*args, **kwargs)

Method to generate key material (format depending on the type of scheme) for this scheme.

Parameters:

• *args (Any) – Required arguments to generate said key material.

• **kwargs (Any) – Required keyword arguments to generate said key material.

Return type:

TypeVar(KM)