There is no set of parameters that I've been able to find that makes it possible to encrypt anything with des-ede3 or DES-EDE3 under JRuby. It is trivially possible in MRI:

if defined?(JRUBY_VERSION)
  puts 'Applying https://github.com/jruby/jruby/wiki/UnlimitedStrengthCrypto'
  security_class = java.lang.Class.for_name('javax.crypto.JceSecurity')
  restricted_field = security_class.get_declared_field('isRestricted')
  restricted_field.accessible = true
  restricted_field.set(nil, false)
end

require 'openssl'
require 'securerandom'

cipher = OpenSSL::Cipher.new('des-ede3')
cipher.encrypt
cipher.key = SecureRandom.random_bytes(64)
cipher.iv = SecureRandom.random_bytes(64)
puts (cipher.update('sup3rs33kr3t') + cipher.final).inspect

Output in MRI: "\x93\f\x95U\xBD\xCB\xB6\xD0\xDAt\x91{%\xED\xCF\xD8"
Output in JRuby without jruby-openssl: "OpenSSL::Cipher::CipherError: DES key too long - should be 8 bytes: possibly you need to install Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files for your JRE"

Changing the key length to 8 bytes results in "OpenSSL::Cipher::CipherError: key length too short" on all VMs.

This works with jruby-openssl installed, but the presence of jruby-openssl causes many other problems (see jruby/jruby-openssl#31).