Botan::Classic_McEliece_Parameters Class Reference

#include <cmce_parameters.h>

Public Member Functions
size_t	ciphertext_size () const
	The byte size of the ciphertext.
size_t	encode_out_size () const
	The output byte size of the encoding algorithm. See ISO 7.3.
size_t	estimated_strength () const
	The estimated bit security strength of the Classic McEliece instance.
Classic_McEliece_GF	gf (CmceGfElem elem) const
	Create a GF(q) element using the modulus for the current instance.
std::unique_ptr< HashFunction >	hash_func () const
	Create an instance of the hash function Hash(x) used in Classic McEliece's Decaps and Encaps algorithms.
bool	is_f () const
bool	is_pc () const
size_t	m () const
	The degree of the Classic McEliece instance's underlying Galois Field, i.e. GF(q) = GF(2^m).
size_t	n () const
	The code length of the Classic McEliece instance.
OID	object_identifier () const
	The OID for the Classic McEliece instance.
Classic_McEliece_Parameter_Set	parameter_set () const
	The parameter set for this Classic McEliece instance.
size_t	pk_no_cols () const
	The number of columns in the public key's matrix.
size_t	pk_no_rows () const
	The number of rows in the public key's matrix.
size_t	pk_row_size_bytes () const
	The number of bytes for each row in the public key's matrix.
size_t	pk_size_bytes () const
	The number of bytes for the public key.
CmceGfMod	poly_f () const
	The monic irreducible polynomial f(z) of degree m over GF(2). Used for modular reduction in GF(2^m).
const Classic_McEliece_Polynomial_Ring &	poly_ring () const
	The underlying polynomial ring.
std::unique_ptr< XOF >	prg (std::span< const uint8_t > seed) const
	Create a seeded XOF object representing Classic McEliece's PRG. See Classic McEliece ISO 9.1.
size_t	q () const
	The field size of the Classic McEliece instance's underlying Galois Field, i.e. GF(q) is the underlying field.
size_t	sk_alpha_control_bytes () const
	The length of the byte representation of the field ordering's control bits. See ISO 9.2.12.
size_t	sk_poly_g_bytes () const
	The length of the byte representation of the minimal polynomial g. See ISO 9.2.12.
size_t	sk_s_bytes () const
	The byte length of the seed s. s is used for implicit rejection. See ISO 9.2.12.
size_t	sk_size_bytes () const
	The byte length of the secret key sk. See ISO 9.2.12.
size_t	t () const
	The weight of the error vector e.
size_t	tau () const
	Constant tau for fixed-weight vector generation. (see Classic McEliece ISO 8.4)

Static Public Member Functions
static Classic_McEliece_Parameters	create (Classic_McEliece_Parameter_Set set)
	Create Classic McEliece parameters from a parameter set.
static Classic_McEliece_Parameters	create (const OID &oid)
	Create Classic McEliece parameters from an OID.
static Classic_McEliece_Parameters	create (std::string_view name)
	Create Classic McEliece parameters from a parameter set name.
static constexpr size_t	ell ()
	Bit output length of the hash function H.
static constexpr size_t	hash_out_bytes ()
	The byte size of the hash output.
static constexpr size_t	mu ()
	Constant mu for semi-systematic matrix creation. (see Classic McEliece ISO 7.2.3)
static constexpr size_t	nu ()
	Constant nu for semi-systematic matrix creation. (see Classic McEliece ISO 7.2.3)
static constexpr size_t	seed_len ()
	The byte length of the seed delta. See ISO 9.2.12.
static constexpr size_t	sigma1 ()
	The number of bits each GF element is encoded with.
static constexpr size_t	sigma2 ()
	Constant for field-ordering generation. (see Classic McEliece ISO 8.2)
static constexpr size_t	sk_c_bytes ()
	The byte length of the column selection c. See ISO 9.2.12.

Detailed Description

Container for all Classic McEliece parameters.

Definition at line 29 of file cmce_parameters.h.

Member Function Documentation

ciphertext_size()

size_t Botan::Classic_McEliece_Parameters::ciphertext_size ( ) const

inline

The byte size of the ciphertext.

Definition at line 229 of file cmce_parameters.h.

                                     {
         if(is_pc()) {
            // C_0 + C_1
            return encode_out_size() + hash_out_bytes();
         } else {
            return encode_out_size();
         }
      }

create() [1/3]

Classic_McEliece_Parameters Botan::Classic_McEliece_Parameters::create ( Classic_McEliece_Parameter_Set set )

static

Create Classic McEliece parameters from a parameter set.

Definition at line 95 of file cmce_parameters.cpp.

                                                                                                  {
   auto poly_ring = determine_poly_ring(set);
 
   switch(set.code()) {
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_348864:
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_348864f:
         return Classic_McEliece_Parameters(set, 12, 3488, std::move(poly_ring));
 
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_460896:
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_460896f:
         return Classic_McEliece_Parameters(set, 13, 4608, std::move(poly_ring));
 
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128:
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128f:
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128pc:
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128pcf:
         return Classic_McEliece_Parameters(set, 13, 6688, std::move(poly_ring));
 
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119:
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119f:
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119pc:
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119pcf:
         return Classic_McEliece_Parameters(set, 13, 6960, std::move(poly_ring));
 
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128:
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128f:
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128pc:
      case Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128pcf:
         return Classic_McEliece_Parameters(set, 13, 8192, std::move(poly_ring));
   }
   BOTAN_ASSERT_UNREACHABLE();
}

References BOTAN_ASSERT_UNREACHABLE, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_348864, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_348864f, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_460896, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_460896f, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128f, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128pc, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128pcf, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119f, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119pc, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119pcf, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128f, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128pc, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128pcf, Botan::Classic_McEliece_Parameter_Set::code(), and poly_ring().

Referenced by Botan::Classic_McEliece_PrivateKey::Classic_McEliece_PrivateKey(), Botan::Classic_McEliece_PrivateKey::Classic_McEliece_PrivateKey(), Botan::Classic_McEliece_PublicKey::Classic_McEliece_PublicKey(), create(), and create().

create() [2/3]

Classic_McEliece_Parameters Botan::Classic_McEliece_Parameters::create ( const OID & oid )

static

Create Classic McEliece parameters from an OID.

Definition at line 132 of file cmce_parameters.cpp.

                                                                              {
   return create(Classic_McEliece_Parameter_Set::from_oid(oid));
}

References create(), and Botan::Classic_McEliece_Parameter_Set::from_oid().

create() [3/3]

Classic_McEliece_Parameters Botan::Classic_McEliece_Parameters::create ( std::string_view name )

static

Create Classic McEliece parameters from a parameter set name.

Definition at line 128 of file cmce_parameters.cpp.

                                                                                   {
   return Classic_McEliece_Parameters::create(Classic_McEliece_Parameter_Set::from_string(name));
}

References create(), Botan::Classic_McEliece_Parameter_Set::from_string(), and name.

ell()

static constexpr size_t Botan::Classic_McEliece_Parameters::ell ( )

inlinestaticconstexpr

Bit output length of the hash function H.

Definition at line 110 of file cmce_parameters.h.

{ return 256; }

encode_out_size()

size_t Botan::Classic_McEliece_Parameters::encode_out_size ( ) const

inline

The output byte size of the encoding algorithm. See ISO 7.3.

Definition at line 217 of file cmce_parameters.h.

{ return ceil_division<size_t>(m() * t(), 8); }

estimated_strength()

size_t Botan::Classic_McEliece_Parameters::estimated_strength

(

)

const

The estimated bit security strength of the Classic McEliece instance.

Reference: Classic McEliece NIST Round 4 submission, Guide for security reviewers

Definition at line 148 of file cmce_parameters.cpp.

                                                             {
   // Classic McEliece NIST Round 4 submission, Guide for security reviewers, Table 1:
   // For each instance, the minimal strength against the best attack (with free memory access)
   // is used as the overall security strength estimate. The strength is capped at 256, since the
   // seed is only 256 bits long.
   switch(m_set.code()) {
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_348864:
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_348864f:
         return 140;
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_460896:
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_460896f:
         return 179;
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128:
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128f:
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128pc:
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128pcf:
         return 246;
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119:
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119f:
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119pc:
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119pcf:
         return 245;
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128:
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128f:
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128pc:
      case Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128pcf:
         return 256;  // 275 in the document. Capped at 256 because of the seed length.
   }
   BOTAN_ASSERT_UNREACHABLE();
}

References BOTAN_ASSERT_UNREACHABLE, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_348864, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_348864f, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_460896, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_460896f, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128f, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128pc, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128pcf, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119f, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119pc, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119pcf, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128f, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128pc, Botan::Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128pcf, and Botan::Classic_McEliece_Parameter_Set::code().

gf()

Classic_McEliece_GF Botan::Classic_McEliece_Parameters::gf ( CmceGfElem elem ) const

inline

Create a GF(q) element using the modulus for the current instance.

Parameters

elem	The GF(q) element value.

Returns

The GF(q) element.

Definition at line 265 of file cmce_parameters.h.

{ return Classic_McEliece_GF(elem, poly_f()); }

hash_func()

std::unique_ptr< HashFunction > Botan::Classic_McEliece_Parameters::hash_func ( ) const

inline

Create an instance of the hash function Hash(x) used in Classic McEliece's Decaps and Encaps algorithms.

Returns

a new instance of the hash function.

Definition at line 257 of file cmce_parameters.h.

{ return HashFunction::create_or_throw("SHAKE-256(256)"); }

hash_out_bytes()

static constexpr size_t Botan::Classic_McEliece_Parameters::hash_out_bytes ( )

inlinestaticconstexpr

The byte size of the hash output.

This is also the size of the shared key K that is a hash output.

Definition at line 224 of file cmce_parameters.h.

{ return ell() / 8; }

is_f()

bool Botan::Classic_McEliece_Parameters::is_f ( ) const

inline

     @returns true iff the instance is a fast (F) instance, i.e. if the semi-systematic
     matrix creation is used.

`

Definition at line 72 of file cmce_parameters.h.

                        {
         return (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_348864f) ||
                (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_460896f) ||
                (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128f) ||
                (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128pcf) ||
                (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119f) ||
                (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119pcf) ||
                (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128f) ||
                (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128pcf);
      }

Referenced by Botan::Classic_McEliece_Matrix::create_matrix_and_apply_pivots().

is_pc()

bool Botan::Classic_McEliece_Parameters::is_pc ( ) const

inline

Returns

true iff the instance is a plaintext confirmation (PC) instance.

Definition at line 59 of file cmce_parameters.h.

                         {
         return (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128pc) ||
                (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_6688128pcf) ||
                (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119pc) ||
                (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_6960119pcf) ||
                (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128pc) ||
                (m_set == Classic_McEliece_Parameter_Set::ClassicMcEliece_8192128pcf);
      }

m()

size_t Botan::Classic_McEliece_Parameters::m ( ) const

inline

The degree of the Classic McEliece instance's underlying Galois Field, i.e. GF(q) = GF(2^m).

Definition at line 86 of file cmce_parameters.h.

{ return m_m; }

Referenced by Botan::Classic_McEliece_Field_Ordering::create_from_control_bits().

mu()

static constexpr size_t Botan::Classic_McEliece_Parameters::mu ( )

inlinestaticconstexpr

Constant mu for semi-systematic matrix creation. (see Classic McEliece ISO 7.2.3)

Definition at line 125 of file cmce_parameters.h.

{ return 32; }

Referenced by Botan::Classic_McEliece_Field_Ordering::permute_with_pivots().

n()

size_t Botan::Classic_McEliece_Parameters::n ( ) const

inline

The code length of the Classic McEliece instance.

E.g. the Classic McEliece matrix H is of size m*t x n, the encoded error vector is, therefore, of size n.

Definition at line 100 of file cmce_parameters.h.

{ return m_n; }

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::check_key(), and Botan::Classic_McEliece_Matrix::mul().

nu()

static constexpr size_t Botan::Classic_McEliece_Parameters::nu ( )

inlinestaticconstexpr

Constant nu for semi-systematic matrix creation. (see Classic McEliece ISO 7.2.3)

Definition at line 130 of file cmce_parameters.h.

{ return 64; }

Referenced by Botan::Classic_McEliece_Field_Ordering::permute_with_pivots().

object_identifier()

OID Botan::Classic_McEliece_Parameters::object_identifier

(

)

const

The OID for the Classic McEliece instance.

Definition at line 136 of file cmce_parameters.cpp.

                                                         {
   return OID::from_string(m_set.to_string());
}

References Botan::OID::from_string(), and Botan::Classic_McEliece_Parameter_Set::to_string().

parameter_set()

Classic_McEliece_Parameter_Set Botan::Classic_McEliece_Parameters::parameter_set ( ) const

inline

The parameter set for this Classic McEliece instance.

Definition at line 49 of file cmce_parameters.h.

{ return m_set; }

pk_no_cols()

size_t Botan::Classic_McEliece_Parameters::pk_no_cols ( ) const

inline

The number of columns in the public key's matrix.

Note that this is only the column number of the submatrix T (with H = (I_mt | T)), which is stored in the public key. The column number of the whole matrix H is n. This constant is also denoted as k in the spec.

Definition at line 200 of file cmce_parameters.h.

{ return n() - pk_no_rows(); }

Referenced by Botan::Classic_McEliece_Matrix::Classic_McEliece_Matrix().

pk_no_rows()

size_t Botan::Classic_McEliece_Parameters::pk_no_rows ( ) const

inline

The number of rows in the public key's matrix.

Definition at line 191 of file cmce_parameters.h.

{ return t() * m(); }

Referenced by Botan::Classic_McEliece_Matrix::Classic_McEliece_Matrix(), Botan::Classic_McEliece_Matrix::mul(), and Botan::Classic_McEliece_Field_Ordering::permute_with_pivots().

pk_row_size_bytes()

size_t Botan::Classic_McEliece_Parameters::pk_row_size_bytes ( ) const

inline

The number of bytes for each row in the public key's matrix.

Definition at line 205 of file cmce_parameters.h.

{ return (pk_no_cols() + 7) / 8; }

Referenced by Botan::Classic_McEliece_Matrix::Classic_McEliece_Matrix(), and Botan::Classic_McEliece_Matrix::mul().

pk_size_bytes()

size_t Botan::Classic_McEliece_Parameters::pk_size_bytes ( ) const

inline

The number of bytes for the public key.

Equal to the byte size of the CMCE matrix.

Definition at line 212 of file cmce_parameters.h.

{ return pk_no_rows() * pk_row_size_bytes(); }

Referenced by Botan::Classic_McEliece_Matrix::Classic_McEliece_Matrix().

poly_f()

CmceGfMod Botan::Classic_McEliece_Parameters::poly_f ( ) const

inline

The monic irreducible polynomial f(z) of degree m over GF(2). Used for modular reduction in GF(2^m).

Definition at line 146 of file cmce_parameters.h.

{ return m_poly_ring.poly_f(); }

Referenced by Botan::Classic_McEliece_Field_Ordering::create_field_ordering(), Botan::Classic_McEliece_Field_Ordering::create_from_control_bits(), and Botan::Classic_McEliece_PrivateKeyInternal::from_bytes().

poly_ring()

const Classic_McEliece_Polynomial_Ring & Botan::Classic_McEliece_Parameters::poly_ring ( ) const

inline

The underlying polynomial ring.

Definition at line 241 of file cmce_parameters.h.

{ return m_poly_ring; }

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::check_key(), and create().

prg()

std::unique_ptr< XOF > Botan::Classic_McEliece_Parameters::prg

(

std::span< const uint8_t >

seed

)

const

Create a seeded XOF object representing Classic McEliece's PRG. See Classic McEliece ISO 9.1.

Parameters

seed	The seed used for the XOF.

Definition at line 179 of file cmce_parameters.cpp.

                                                                                     {
   BOTAN_ASSERT_EQUAL(seed.size(), 32, "Valid seed length");
   auto xof = XOF::create_or_throw("SHAKE-256");
 
   xof->update(std::array<uint8_t, 1>({64}));
   xof->update(seed);
 
   return xof;
}

References BOTAN_ASSERT_EQUAL, and Botan::XOF::create_or_throw().

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::check_key().

q()

size_t Botan::Classic_McEliece_Parameters::q ( ) const

inline

The field size of the Classic McEliece instance's underlying Galois Field, i.e. GF(q) is the underlying field.

Definition at line 92 of file cmce_parameters.h.

{ return (size_t(1) << m_m); }

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::check_key(), and Botan::Classic_McEliece_Field_Ordering::create_field_ordering().

seed_len()

static constexpr size_t Botan::Classic_McEliece_Parameters::seed_len ( )

inlinestaticconstexpr

The byte length of the seed delta. See ISO 9.2.12.

Definition at line 158 of file cmce_parameters.h.

{ return ell() / 8; }

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::from_bytes(), and Botan::Classic_McEliece_KeyPair_Internal::generate().

sigma1()

static constexpr size_t Botan::Classic_McEliece_Parameters::sigma1 ( )

inlinestaticconstexpr

The number of bits each GF element is encoded with.

Definition at line 115 of file cmce_parameters.h.

{ return 16; }

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::check_key().

sigma2()

static constexpr size_t Botan::Classic_McEliece_Parameters::sigma2 ( )

inlinestaticconstexpr

Constant for field-ordering generation. (see Classic McEliece ISO 8.2)

Definition at line 120 of file cmce_parameters.h.

{ return 32; }

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::check_key(), and Botan::Classic_McEliece_Field_Ordering::create_field_ordering().

sk_alpha_control_bytes()

size_t Botan::Classic_McEliece_Parameters::sk_alpha_control_bytes ( ) const

inline

The length of the byte representation of the field ordering's control bits. See ISO 9.2.12.

Definition at line 173 of file cmce_parameters.h.

{ return (2 * m() - 1) * (size_t(1) << (m() - 4)); }

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::from_bytes().

sk_c_bytes()

static constexpr size_t Botan::Classic_McEliece_Parameters::sk_c_bytes ( )

inlinestaticconstexpr

The byte length of the column selection c. See ISO 9.2.12.

Definition at line 163 of file cmce_parameters.h.

{ return 8; }

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::from_bytes().

sk_poly_g_bytes()

size_t Botan::Classic_McEliece_Parameters::sk_poly_g_bytes ( ) const

inline

The length of the byte representation of the minimal polynomial g. See ISO 9.2.12.

Definition at line 168 of file cmce_parameters.h.

{ return t() * sizeof(uint16_t); }

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::from_bytes().

sk_s_bytes()

size_t Botan::Classic_McEliece_Parameters::sk_s_bytes ( ) const

inline

The byte length of the seed s. s is used for implicit rejection. See ISO 9.2.12.

Definition at line 178 of file cmce_parameters.h.

{ return n() / 8; }

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::from_bytes().

sk_size_bytes()

size_t Botan::Classic_McEliece_Parameters::sk_size_bytes ( ) const

inline

The byte length of the secret key sk. See ISO 9.2.12.

Definition at line 183 of file cmce_parameters.h.

                                   {
         // ISO 9.2.12: sk = (delta, c, g, alpha(control bits), s)
         return seed_len() + sk_c_bytes() + sk_poly_g_bytes() + sk_alpha_control_bytes() + sk_s_bytes();
      }

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::from_bytes().

t()

size_t Botan::Classic_McEliece_Parameters::t ( ) const

inline

The weight of the error vector e.

Definition at line 105 of file cmce_parameters.h.

{ return m_poly_ring.degree(); }

Referenced by Botan::Classic_McEliece_PrivateKeyInternal::check_key().

tau()

size_t Botan::Classic_McEliece_Parameters::tau ( ) const

inline

Constant tau for fixed-weight vector generation. (see Classic McEliece ISO 8.4)

Definition at line 135 of file cmce_parameters.h.

                         {
         // Section 8.4 of ISO:
         // The integer tau is defined as t if n=q; as 2t if q/2<=n<q; as 4t if q/4<=n<q/2; etc
         size_t tau_fact = size_t(1) << (m() - floor_log2(n()));
         return tau_fact * t();
      }

References Botan::floor_log2().

---

The documentation for this class was generated from the following files:

• src/lib/pubkey/classic_mceliece/cmce_parameters.h
• src/lib/pubkey/classic_mceliece/cmce_parameters.cpp