Trustless provably fair information marketplace
==================================================================
"PayPub: Trustless payments for information publishing on Bitcoin"
    Scheme by Peter Todd
    Code by Amir Taaki

    ###############################
    # EARLY NON-SERIOUS PROTOTYPE #
    ###############################

* Distribute an encrypted file to the world.
* Reveal some (provably fair) random section of the contents to prove
  the legitimacy of its contents.
* People bid on the remaining parts.
* Leaker redeeming funds automatically releases the decryption key
  allowing people to unlock the remaining parts of the file.

* NO CENTRAL OPERATOR.
* NO IDENTITY NEEDED.
* NO INTERACTION WITH LEAKER REQUIRED.

See EXPLANATION. Imagine once this is a simple piece of software for
anyone to use (leaker: import file, add info, prove possession,
bidder: verify, bid on chunk, unlock) of course running all over Tor
with a nice use interface.

Decentralised way to leak and get paid for any FILE or information:
proprietary software, opensource software, corporate documents, firmware
drivers, movies .etc

I want to put out information and get $$$

  $ pp_start TESTFILE 100
  58 chunks created.
  Choose a future block height and a number of chunks to release.
  Announce them to the world.

Announce the HEIGHT to the world.
Make the _public_chunks/ directory publically available for download.

  "At block HEIGHT 341000 (Expected Nov 11 2014), I will prove
   possession of the files encrypted at this location:
     <torrent:...>
   by releasing 18 of the 58 chunks." -Leaker

Once block hash becomes known:

  $ pp_prove TESTFILE 100 0000000000000000251ed5ba6bc475c13e15550475e4049e153a06b78b5a8a50 10 > proof_file
  $ cat proof_file
  20 03e9fc6592798125ede112430e0b8beb30dacd9787f061883bf0bfa43e2ca8d378
  34 036675c1d13a0112f28956e61475551c4bc53b8b5f6a8c0799fd9bb9f968cfc8ce
  26 02267eeac444549d63836ff1d098de2b045d0f897849c50120645d6982463d0aa4
  26 02267eeac444549d63836ff1d098de2b045d0f897849c50120645d6982463d0aa4
  4 02096ec2b83982ddef77ce2e1628e90ff51ac04eaa9870326a38b3f15112577843
  26 02267eeac444549d63836ff1d098de2b045d0f897849c50120645d6982463d0aa4
  5 034633adfee376bed397acaa576196fff39fa8257080be0914e22cb92c2c90fe26
  19 030c6624306007688c3f27e86b6add811c4a83f1bde2e728e62458c631f76359e5
  21 028e3f035d4ec79e6afa3a8a90a95dda4f2ced04d1e5bb77321254bea3e5545ec5
  33 03dd42d8d4134491aee30de991350547e87f100ac9d4e0a1ac6b94150cd2e2d2b8
  39 023a9a24584ddd2788136128d2c9d84bf4fae9d8063fb691b16eaf62d55193d6b7
  14 02c920dbd95487749ea8cd602ffe00c6f54f396e4e2a3c2cb0ee8507a761f7505f
  5 034633adfee376bed397acaa576196fff39fa8257080be0914e22cb92c2c90fe26

Reveal these to your audience by distributing proof_file. They can use this
file to unlock chunks and verify their authenticity.

  $ pp_unlock_all proof_file TESTFILE_public_chunks/ 0000000000000000251ed5ba6bc475c13e15550475e4049e153a06b78b5a8a50

Which is just a bash script that repeatedly calls for each line in the
proof_file:

  $ pp_unlock TESTFILE_public_chunks/CHUNK.20 0000000000000000251ed5ba6bc475c13e15550475e4049e153a06b78b5a8a50 03e9fc6592798125ede112430e0b8beb30dacd9787f061883bf0bfa43e2ca8d378
  // Creates CHUNK.20.decrypted

The leaker can choose to reveal subsequent blocks by spending money send
to the addresses in _public_chunks/ADDRS file.
Spending money from those addresses, reveals the public key which is used
to decrypt other chunks.

To do that, the leaker simply needs to import these keys into his wallet
and spend any funds at those addresses:

  $ pp_secrets TESTFILE 100
  L265LXaXqh5TX97voQjz4Wo7Qpyoj8aCxotZYoYsG1vA72oiRTRN
  L4qJhBVQhHVWQDznzaUoiBkBBpZubJAoLuwhNGW1AdgUoLmXpZSC
  L37xPybVaSmBKdL6s3SgKUzsmAuBDRsws6oUjXKzz8TgNiypcsvi
  L2ob4c74UB6rbH7YPA1s6ATDLgrDHNtRB8rUhjL2xzqrXNztQzH6
  KywiFkzENUKvuMrFGnbSN3PemGHM555QtXhRXAk3D8b1VJwRrc4X
    ...

To find the pubkeys for an ADDRESS, use the tool pp_check_addr:

  $ ./pp_check_addr 1Ksv3HoCAn75uMfXtyWLgauUQv3gEa389A
  Fetching transaction...
  02e1746dc1da27a5d4be9be4855016fc6fdd6f29b5a198239978dafdf7dd647656

Merge the decrypted files back together again using:

  $ ./pp_merge TESTFILE_public_chunks/ 58

(where 58 is the number of chunks... it's a simple bash script.)