[Bitcoin-development] Identity protocol observation

Daniel Lidstrom lidstrom83 at gmail.com
Thu Oct 3 13:35:32 UTC 2013

A couple more thoughts on this:

1) Both c and k can be kept if c is pronounced 'ch', giving ~10.9 bits per
2) An extra phoneme (4 encode 43 bits total) gives room to put extra
information into the name, e.g. the first 5 bits could be input as the key
to a PRP that permutes the last 38 back to a standard encoding of a tx
location.  This would give the user 32 random names per sacrifice to choose
from, and 38 bits to encode its location in the blockchain, which is enough
for pretty large blocks.

Sample 4 phoneme names:

They're not that bad IMHO, especially if you get to pick a decent one from
a bunch.

On Thu, Oct 3, 2013 at 3:35 AM, Daniel Lidstrom <lidstrom83 at gmail.com>wrote:

> The location of a tx in the blockchain can be encoded in n=log2(h)+log2(t)
> bits, where h is the block height, and t is the number of transactions in
> the block.  Currently h~250,000 and t~500, so n~27.  A CVC phoneme encodes
> ~10.7 bits *, so a transaction today can be located in the blockchain with
> 3 of these, e.g. reb-mizvig.  This is reasonably short, readable and
> memorable.
> The identity protocol Jeff Garzik is working on will link a public key
> fingerprint to a miner sacrifice transaction.  This tx could in turn be
> uniquely described with a short name as above.  Associating this name with
> the public key becomes secure once the tx is sufficiently buried in the
> blockchain.  In the identity protocol, lightweight clients check the
> validity of a sacrifice tx by checking that its merkle path is valid.  But
> this path encodes, via the ordering of the hashes at each level, the
> location of the transaction in the block, so the lightweight client can
> verify the sacrifice tx's short name using only the information he already
> has.
> Some more random names:
> vec-halhic
> wom-vizpyd
> guv-zussof
> jog-copwug
> seg-rizges
> jyg-somgod
> pax-synjem
> zyg-zuxdyj
> gid-mutdyj
> rel-hyrdaj
> Sources of inspiration:
> urbit.org
> https://en.bitcoin.it/wiki/Identity_protocol_v1
> * This is somewhat restricted: I disallowed q for obvious reasons and k
> because it conflicts with c, and c looks much softer and less like
> Klingon.  H is allowed for the first consonant, but not the second, and x
> is allowed for the last one, but not the first one.  Y is a vowel, but not
> a consonant.  Maybe these weren't quite the right choices.  Paint away!
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