Hi Gavin / Luke,
BIP-13 again... I started to implement a bitfield based parsing of the version
byte using the description I got from Luke, but I then discovered that it does
not hold:
Network class:
00xx - main network
01xx - reserved
10xx - reserved
11xx - test network
Network:
xx00 - bitcoin
xx01 - reserved
xx10 - OTHER (next octet)
xx11 - Namecoin
Network specific:
000y - PubKeyHash
001y - reserved
010y - p2sh
011y - public key (raw)
100y - signature
101y - reserved
110y - private key (raw)
111y - OTHER (next octet)
However, the definitions en base58.h are:
PUBKEY_ADDRESS = 0, ()
SCRIPT_ADDRESS = 5, (0101)
PUBKEY_ADDRESS_TEST = 111, (0110) !!!
SCRIPT_ADDRESS_TEST = 196, (11000100) !!!
[as a side note litecoin is 48 (0011) and namecoin is 52 (00110100)]
So there is no logic ?? I have searched the mailing list and the forum for
discussions on this but found it hard to find any. If I overlooked something
please direct me.
Cheers,
M
PS: I have said so before, but it would *really* be nice if discussions /
conclusions / irc-summaries were taking place at one place - e.g. at the
bitcoin-dev mailing list, not at 5-10 different threads in bitcointalk or in
bip notes or solely on IRC...
On 20/02/2012, at 18:17, Gavin Andresen wrote:
RE:
base58-encode: [one-byte network ID][20-byte hash][one-byte address
class][3-byte checksum]
How will the code distinguish between the old scheme:
[one-byte-version][20-byte-hash][4-byte-checksum]
and the new?
1 in 256 old addresses will have a first-byte-of-checksum that matches the
new address class; I guess the code would do something like:
a) If the 4-byte checksum matches, then assume it is a singlesig address (1
in 2^32 multisig addresses will incorrectly match)
b) If the one-byte-address-class and 3-byte checksum match, then it is a
valid p2sh
c) Otherwise, invalid address
The 1 in 2^32 multisig addresses also being valid singlesig addresses makes
me think this scheme won't work-- an attacker willing to generate 8 billion
or so ECDSA keys could generate a single/multisig collision. I'm not sure
how that could be leveraged to their advantage, but I bet they'd find a way.
RE: should it be a BIP: The BIP process is described in BIP 0001, and you're
following it perfectly so far:
1) Post a rough draft of the idea here to see if there's any chance it'll be
adopted
2) Assuming a positive response and no major flaws: write up a draft BIP
3) Post the draft BIP here, where it can be picked apart.
4) Assuming no major flaws, ask the BIP editor (Amir) for a BIP number
I'd also encourage you to actually implement your idea between steps 3 and 4.
But in this particular case, I think an attacker being able to create
singlesig/p2sh address collisions counts as a major flaw.
--
--
Gavin Andresen
Michael Gronager, PhD
Director, Ceptacle
Jens Juels Gade 33
2100 Copenhagen E
Mobile: +45 31 45 14 01
E-mail: grona...@ceptacle.com
Web: http://www.ceptacle.com/
--
Virtualization Cloud Management Using Capacity Planning
Cloud computing makes use of virtualization - but cloud computing
also focuses on allowing computing to be delivered as a service.
http://www.accelacomm.com/jaw/sfnl/114/51521223/
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