mks-m

require 'openssl'
require 'base64'

# key and iv stored in configs, generated using:
# cipher = OpenSSL::Cipher::Cipher.new('AES-256-CBC').encrypt
# key = cipher.random_key
# iv = cipher.random_iv

def encrypt_id(key, iv, id)
  cipher = OpenSSL::Cipher::Cipher.new('AES-256-CBC').encrypt

mks-m

Bitcoin Full Node on AWS Free Tier

Provisioning

• Launch one T2 micro instance, using Ubuntu 14.04 LTS AMI.
• Open SSH and Bitcoin Protocol TCP ports: 22, 8333.
• Attach 150GB EBS (General-Purpose SSD) volume for blockchain storage to /dev/sdf.

The pricing would be ~$15/month. See here for more details.

mks-m

# just speed test for http://stackoverflow.com/questions/11502629/how-to-do-number-to-string-suffix/11502715#11502715

# if we properly test int<->str conversion the log_10 method is about 30% faster

begin
  int = 5

  a = Time.now.to_f
  10_000_000.times { int.to_s.ljust(3, "0").to_i }
  puts Time.now.to_f - a # => 1.3s