| 67 | } |
| 68 | |
| 69 | template <class T> void DL_FixedBasePrecomputationImpl<T>::PrepareCascade(const DL_GroupPrecomputation<Element> &i_group, std::vector<BaseAndExponent<Element> > &eb, const Integer &exponent) const |
| 70 | { |
| 71 | const AbstractGroup<T> &group = i_group.GetGroup(); |
| 72 | |
| 73 | Integer r, q, e = exponent; |
| 74 | bool fastNegate = group.InversionIsFast() && m_windowSize > 1; |
| 75 | unsigned int i; |
| 76 | |
| 77 | for (i=0; i+1<m_bases.size(); i++) |
| 78 | { |
| 79 | Integer::DivideByPowerOf2(r, q, e, m_windowSize); |
| 80 | std::swap(q, e); |
| 81 | if (fastNegate && r.GetBit(m_windowSize-1)) |
| 82 | { |
| 83 | ++e; |
| 84 | eb.push_back(BaseAndExponent<Element>(group.Inverse(m_bases[i]), m_exponentBase - r)); |
| 85 | } |
| 86 | else |
| 87 | eb.push_back(BaseAndExponent<Element>(m_bases[i], r)); |
| 88 | } |
| 89 | eb.push_back(BaseAndExponent<Element>(m_bases[i], e)); |
| 90 | } |
| 91 | |
| 92 | template <class T> T DL_FixedBasePrecomputationImpl<T>::Exponentiate(const DL_GroupPrecomputation<Element> &group, const Integer &exponent) const |
| 93 | { |