Class: BSV::Primitives::KeyShares

Inherits:
Object
  • Object
show all
Defined in:
lib/bsv/primitives/key_shares.rb

Overview

A set of Shamir’s Secret Sharing shares derived from a private key.

Holds the evaluation points (shares), a reconstruction threshold, and an integrity string for verifying that recombined shares produce the correct key. Supports serialisation to and from a human-readable backup format.

Backup format per share: “Base58(x).Base58(y).threshold.integrity”

This format is compatible with the Go and TypeScript reference SDKs.

Examples:

Round-trip through backup format

shares  = key.to_key_shares(2, 5)
backup  = shares.to_backup_format
rebuilt = KeyShares.from_backup_format(backup[0..1])
key     = PrivateKey.from_key_shares(rebuilt)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(points, threshold, integrity) ⇒ KeyShares

Returns a new instance of KeyShares.

Parameters:

  • points (Array<PointInFiniteField>) —

    share points

  • threshold (Integer) —

    reconstruction threshold

  • integrity (String) —

    integrity check string



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# File 'lib/bsv/primitives/key_shares.rb', line 33

def initialize(points, threshold, integrity)
  @points    = points
  @threshold = threshold
  @integrity = integrity
end

Instance Attribute Details

#integrity ⇒ String (readonly)

Returns first 8 hex characters of the Hash160 of the compressed public key.

Returns:

  • (String) —

    first 8 hex characters of the Hash160 of the compressed public key



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# File 'lib/bsv/primitives/key_shares.rb', line 28

def integrity
  @integrity
end

#points ⇒ Array<PointInFiniteField> (readonly)

Returns the share points.

Returns:



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# File 'lib/bsv/primitives/key_shares.rb', line 22

def points
  @points
end

#threshold ⇒ Integer (readonly)

Returns the minimum number of shares required to reconstruct the key.

Returns:

  • (Integer) —

    the minimum number of shares required to reconstruct the key



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# File 'lib/bsv/primitives/key_shares.rb', line 25

def threshold
  @threshold
end

Class Method Details

.from_backup_format(shares) ⇒ KeyShares

Deserialise shares from backup format strings.

Each string must have the form “Base58(x).Base58(y).threshold.integrity”. All shares must agree on threshold and integrity.

Parameters:

  • shares (Array<String>) —

    backup-format share strings

Returns:

Raises:

  • (ArgumentError) —

    if any share is malformed or shares are inconsistent



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# File 'lib/bsv/primitives/key_shares.rb', line 47

def self.from_backup_format(shares)
  threshold = 0
  integrity = ''
  points    = shares.each_with_index.map do |share, idx|
    parts = share.split('.', -1)
    raise ArgumentError, "invalid share format in share #{idx}: expected 4 dot-separated parts, got #{share.inspect}" unless parts.length == 4

    x_str, y_str, t_str, i_str = parts

    raise ArgumentError, "threshold not found in share #{idx}" if t_str.empty?
    raise ArgumentError, "integrity not found in share #{idx}" if i_str.empty?

    t_int = Integer(t_str)

    if idx != 0
      raise ArgumentError, "threshold mismatch in share #{idx}" unless threshold == t_int
      raise ArgumentError, "integrity mismatch in share #{idx}" unless integrity == i_str
    end

    threshold = t_int
    integrity = i_str

    PointInFiniteField.from_string("#{x_str}.#{y_str}")
  end

  new(points, threshold, integrity)
end

Instance Method Details

#to_backup_format ⇒ Array<String>

Serialise shares to backup format strings.

Returns:

  • (Array<String>) —

    one backup string per share point



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# File 'lib/bsv/primitives/key_shares.rb', line 78

def to_backup_format
  @points.map { |point| "#{point}.#{@threshold}.#{@integrity}" }
end