def __init__(self, field = None): """ Create a linear feedback shift cryptosystem. INPUT: A string monoid over a binary alphabet. OUTPUT: EXAMPLES:: sage: E = LFSRCryptosystem(FiniteField(2)) sage: E LFSR cryptosystem over Finite Field of size 2 TESTS:: sage: E = LFSRCryptosystem(FiniteField(2)) sage: E == loads(dumps(E)) True TODO: Implement LFSR cryptosystem for arbitrary rings. The current implementation is limited to the finite field of 2 elements only because of the dependence on binary strings. """ if field is None: field = FiniteField(2) if field.cardinality() != 2: raise NotImplementedError("Not yet implemented.") S = BinaryStrings() P = PolynomialRing(FiniteField(2),'x') SymmetricKeyCryptosystem.__init__(self, S, S, None) self._field = field
def __init__(self, field=None): """ Create a linear feedback shift cryptosystem. INPUT: A string monoid over a binary alphabet. OUTPUT: EXAMPLES:: sage: E = LFSRCryptosystem(FiniteField(2)) sage: E LFSR cryptosystem over Finite Field of size 2 TESTS:: sage: E = LFSRCryptosystem(FiniteField(2)) sage: E == loads(dumps(E)) True TODO: Implement LFSR cryptosystem for arbitrary rings. The current implementation is limited to the finite field of 2 elements only because of the dependence on binary strings. """ if field is None: field = FiniteField(2) if field.cardinality() != 2: raise NotImplementedError("Not yet implemented.") S = BinaryStrings() P = PolynomialRing(FiniteField(2), 'x') SymmetricKeyCryptosystem.__init__(self, S, S, None) self._field = field
def __init__(self, field = None): """ Create a shrinking generator cryptosystem. INPUT: A string monoid over a binary alphabet. OUTPUT: EXAMPLES:: sage: E = ShrinkingGeneratorCryptosystem() sage: E Shrinking generator cryptosystem over Finite Field of size 2 """ if field is None: field = FiniteField(2) if field.cardinality() != 2: raise NotImplementedError("Not yet implemented.") S = BinaryStrings() P = PolynomialRing(field, 'x') SymmetricKeyCryptosystem.__init__(self, S, S, None) self._field = field
def __init__(self, field=None): """ Create a shrinking generator cryptosystem. INPUT: A string monoid over a binary alphabet. OUTPUT: EXAMPLES:: sage: E = ShrinkingGeneratorCryptosystem() sage: E Shrinking generator cryptosystem over Finite Field of size 2 """ if field is None: field = FiniteField(2) if field.cardinality() != 2: raise NotImplementedError("Not yet implemented.") S = BinaryStrings() P = PolynomialRing(field, 'x') SymmetricKeyCryptosystem.__init__(self, S, S, None) self._field = field