Ruby: file encryption/decryption with private/public keys

Question

I am searching for an algorithm for file encryption/decryption which satisfies the following requirements:

• Algorithm must be reliable
• Algorithm should

Answer 1

Symmetric Encryption is definitely fast and has excellent support for streaming of very large files.

SymmetricEncryption::Writer.open('my_file.enc') do |file|
  file.write "Hello World\n"
  file.write "Keep this secret"
end

Symmetric Encryption is designed for encrypting data and large files within an organization.

When it comes to sharing files with other organizations then the best option is PGP. For streaming of very large files with PGP consider: IOStreams

IOStreams.writer('hello.pgp', recipient: 'receiver@example.org') do |writer|
  writer.write('Hello World')
  writer.write('and some more')
end

Look at the file iostreams/lib/io_streams/pgp.rb for more PGP examples. It also supports PGP key management directly from Ruby.