RSA Accumulator for Ruby

Cryptographic accumulator based on the strong RSA assumption BBF18 in Ruby.

Installation

Add this line to your application's Gemfile:

gem 'rsa-accumulator'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rsa-accumulator

Usage

Setup accumulator

First, initialize the accumulator. Since the accumulator uses groups of unknown order, it can be generated in following ways:

require 'rsa-accumulator'

# using RSA modulus published by RSA Laboratory
acc = RSA::Accumulator.generate_rsa2048

# using Random RSA modulus with a specified bit length(default value is )
acc = RSA::Accumulator.generate_random(2048)

Adding elements and membership proof

You can add arbitrary String data to the accumulator.

acc.add('a', 'b')
proof = acc.add('c')

You can use inclusion proof to prove that an element exists in an accumulator.

acc.member?(proof)

Non membership proof

You can generate non-membership proof and prove that the elements does not exist in the accumulator.

members = %w(a b)
non_members = %w(c, d)
acc.add(*members)
proof = acc.prove_non_membership(members, non_members)
acc.non_member?(non_members, proof)
=> true

Delete element from accumulator

You can remove elements from the accumulator by providing the inclusion proof.

acc.add('a', 'b')
proof = acc.add('c')
acc.delete(proof)

acc.member?(proof)
=> false

Holding the product of all elements

This feature is experimental and has not been checked against large amounts of data.

acc = RSA::Accumulator.generate_rsa2048(hold_elements: true)
acc.add('a', 'b', 'c')
acc.add('d', 'e')

# acc has product of all elements in acc#products, so you can get membership proof.
proof = acc.prove_membership('b')