ceremonyclient/nekryptology/pkg/sharing/polynomial.go

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2023-07-05 05:32:28 +00:00
//
// Copyright Coinbase, Inc. All Rights Reserved.
//
// SPDX-License-Identifier: Apache-2.0
//
package sharing
import (
"io"
"source.quilibrium.com/quilibrium/monorepo/nekryptology/pkg/core/curves"
)
type Polynomial struct {
Coefficients []curves.Scalar
}
func (p *Polynomial) Init(intercept curves.Scalar, degree uint32, reader io.Reader) *Polynomial {
p.Coefficients = make([]curves.Scalar, degree)
p.Coefficients[0] = intercept.Clone()
for i := 1; i < int(degree); i++ {
p.Coefficients[i] = intercept.Random(reader)
}
return p
}
func (p Polynomial) Evaluate(x curves.Scalar) curves.Scalar {
degree := len(p.Coefficients) - 1
out := p.Coefficients[degree].Clone()
for i := degree - 1; i >= 0; i-- {
out = out.Mul(x).Add(p.Coefficients[i])
}
return out
}