An implementation of the JSON Canonicalization Scheme for Ruby

Implements version 5 of draft-rundgren-json-canonicalization-scheme-05.

Gem Version Build Status Coverage Status


Cryptographic operations like hashing and signing depend on that the target data does not change during serialization, transport, or parsing. By applying the rules defined by JCS (JSON Canonicalization Scheme), data provided in the JSON [RFC8259] format can be exchanged "as is", while still being subject to secure cryptographic operations. JCS achieves this by building on the serialization formats for JSON primitives as defined by ECMAScript [ES6], constraining JSON data to the
I-JSON [RFC7493] subset, and through a platform independent property sorting scheme.

Working document: https://cyberphone.github.io/ietf-json-canon
Published IETF Draft: https://tools.ietf.org/html/draft-rundgren-json-canonicalization-scheme-05

The JSON Canonicalization Scheme concept in a nutshell:

  • Serialization of primitive JSON data types using methods compatible with ECMAScript's JSON.stringify()
  • Lexicographic sorting of JSON Object properties in a recursive process
  • JSON Array data is also subject to canonicalization, but element order remains untouched

Sample Input:

  "numbers": [333333333.33333329, 1E30, 4.50, 2e-3, 0.000000000000000000000000001],
  "string": "\u20ac$\u000F\u000aA'\u0042\u0022\u005c\\\"\/",
  "literals": [null, true, false]

Expected Output:



The library accepts Ruby input and generates canonical JSON via the #to_json_c14n method. This is based on the standard JSON gem's version of #to_json with overloads for Hash, String and Numeric

data = {
  "numbers" => [
  "string" => "€$\u000F\nA'B\"\\\\\"/",
  "literals" => [nil, true, false]

puts data.to_json_c14n


Full documentation available on RubyDoc

Principal Classes




  • Do your best to adhere to the existing coding conventions and idioms.
  • Don't use hard tabs, and don't leave trailing whitespace on any line.
  • Do document every method you add using [YARD][] annotations. Read the [tutorial][YARD-GS] or just look at the existing code for examples.
  • Don't touch the json-ld.gemspec, VERSION or AUTHORS files. If you need to change them, do so on your private branch only.
  • Do feel free to add yourself to the CREDITS file and the corresponding list in the the README. Alphabetical order applies.
  • Do note that in order for us to merge any non-trivial changes (as a rule of thumb, additions larger than about 15 lines of code), we need an explicit [public domain dedication][PDD] on record from you.


This is free and unencumbered public domain software. For more information, see http://unlicense.org/ or the accompanying UNLICENSE file.