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How long have I been on Wikipedia?
Been reading for a few years and made a few small edits. Thought it was time to make an account (2011-02).
Used wikis before?
Several, with various engines, including the original.
Expecting to check in often?
No, sorry. I have IRL-NMIs to service.
Expecting to stick around?
Probably, but there are wikis I haven't been back to in a very long time.


Prove it?[edit]

Experimental Template:User committed identity with iterated SHA512. (I stashed the input my merely-not-public long term storage.)

Committed identity: 782ea2f54f5ad7204c7f7bc005c3646df4a3e56cadeaa27cfebef5319424b06e29a4b355497e04139c59d90f6e8033c1acb0f0d43b6763db68b3ea1ff794fcfd is an iterated SHA512 commitment to this user's real-life identity.

generated with

#! /usr/bin/perl
use strict;
use warnings;
use Digest::SHA qw( sha512_hex );
use YAML 'Dump';
my $last = do { print "Initial secret: "; <STDIN> };
my $blurb = do { print "Per-iteration blurb: "; local $/; <STDIN> };
my %keep;
my $lim = 1E5;
for (my $i=0; $i<=$lim; $i++) {
  $keep{sprintf("%08d", $i)} = $last if $i == 0 || $i+10 >= $lim;
  # include trailing LF in hash, for commandline convenience
  # (echo -n INPUT | sha512sum) vs. (sha512sum<ret>INPUT<ret><ctrl-D>)
  $last = $blurb.sha512_hex($last)."\n";
print Dump(\%keep);

Why iterate?[edit]

It solves the problem where I give the hash input to somebody, and after that have nothing left to offer. With this, I can afford to give away an input about once per hour for ten years.

In the example above, I can reveal

My real name is Bob.
I live in my house.
I can release one hash per hour, starting 2011-02-25t00:00:00 +0000

which you can paste into sha512sum to verify, and then again with the previous (eff3cf7a53d6d43b20948bfdd811f384727704664f5e04949bbe3e1de8dc939ae4a8f5244f9731f5b38702cafde803976d368fa4c5df05c27a7663d3d8eb5ca1) item in the chain. My chain of inputs here is only 105 long because this laptop is slow and I'm impatient, but it's enough.

Each step has the same human-readable input. Maybe the timestamp line should change?

This scheme would need a small program to verify conveniently, anyway. It also needs an extra secret, right at the start of the chain.

Problems remaining[edit]

Many problems with this scheme are discussed at Template talk:User committed identity. I guess I will join in later.