@@ -4,7 +4,7 @@ type: post
44title: Address space
55author: Galen Wolfe-Pauly + Curtis Yarvin
66image: http://urbit.s3.amazonaws.com/16-3-10/blog-3.jpg
7−preview: An overview of the Urbit address-space. Urbit address space is a new kind of cryptographic property, sort of like digital land.
7+preview: An overview of Urbit's cryptographic address space.
88layout: urbit,post
99navmode: navbar
1010navdpad: false
@@ -25,53 +25,68 @@ just read these simplified basics.
2525An Urbit identity, or "ship," is a string like `~firbyr-napbes`. It
2626means nothing, but it's easy to remember and say out loud.
2727`~firbyr-napbes` is actually just a 32-bit number, like an IP address.
28−We turn this number into a string that sounds like a name in a foreign
29−language.
28+We turn this number into a string that sounds like a name from some
29+imaginary foreign country.
3030
3131Technically, a ship is a secure digital identity that you own and
3232control with a cryptographic key, like a Bitcoin wallet. As in
3333Bitcoin, the supply of ships is mathematically limited. This keeps
3434the network friendly, by making spam and abuse expensive.
3535
36−The only way to start a ship is with permission from a ‘parent’,
37−another ship on the network with a shorter name. A 32-bit ship is
38−called a "planet." A 16-bit ship is a "star." An 8-bit ship is a
39−"galaxy.
40−
41−A planet is an identity for a human. Stars and galaxies are network
42−infrastructure. A ship is independent after it's launched, but the
43−right to launch belongs to its parent. So each star can create
44−`65.535` planets; each galaxy can create `255` stars, or (indirectly)
45−`16.776.960` planets.
46−
47−Urbit is born as a centralized network whose address space is entirely
48−owned by its creators, who own the root galaxy `~zod`. But this
49−address space is worthless until distributed. And as it becomes
50−decentralized, it becomes free and independent. The goal is a world
51−completely unlike the one we live in today, where our digital
52−identities are owned by giant corporations.
53−
54−Your Urbit ship is like a digital passport or social security number
55−for a virtual city in the cloud.
36+A ship name is just a number; smaller numbers make shorter names.
37+Shorter names are easier to remember, so they're more valuable. So
38+ships are classified by the number of bits in their name. (A ship
39+name is just a scrambled base-256 representation of the number.)
40+
41+A 32-bit ship (like `~firbyr-napbes`) is called a "planet." A 16-bit
42+ship (like `~pollev)` is a "star." An 8-bit ship (like `~mun`) is a
43+"galaxy." A planet is an identity for an independent, adult human.
44+Stars and galaxies are network infrastructure.
45+
46+Each planet or star is launched by its "parent," the star or galaxy
47+whose number is its bottom half. So the planet `~firbyr-napbes`,
48+`0xdeadbeef` or `3.735.928.559`, is the child of `~pollev`, `0xbeef`
49+or `48.879`, whose parent is `~mun`, `0xef`, `239`. The parent of
50+`~mun` and all galaxies is `~zod`, `0`.
51+
52+If Bitcoin is money, Urbit is land. Much as all real-estate titles in
53+England trace back to William the Conqueror, all certificates in Urbit
54+trace back to `~zod`.
55+
56+But this universe is worthless unless dispersed. It's already quite
57+well fragmented. And as it grows distributed, it grows decentralized.
58+The endpoint is a virtual city of 4 billion (`2^32`) citizens, all
59+owners of their own independent digital identities. The stars and
60+galaxies continue as a federated governance and service network.
61+
62+This city is a social network, a peer-to-peer packet network, and a
63+public-key infrastructure (PKI). In the social layer, your ship is
64+your name. In the packet layer, your ship is your network address.
65+In the PKI, your ship is your cryptographic identity. Perhaps more
66+intuitively, a ship is a sort of pronounceable phone number.
67+
68+And once Urbit is built, no one owns it. No one can control it. It
69+does need governance; it governs itself, as a digital republic.
5670
5771## Details
5872
59−That should be sufficient to understand the high-level goals of the
60−address space. If you want to dive a bit deeper, keep reading.
73+As an Urbit user, these basics are all you need to know. As a
74+developer, a few more details might interest you. (An even more
75+comprehensive treatment is in the [CS paper]()).
6176
6277### Design goals
6378
64−If you know much about identity systems, you know the problem of
65−"Zooko's triangle." An identity system has three goals: a name wants
66−to be secure, human-meaningful, and decentralized. Zooko’s triangle
67−says that a practical identity system can achieve any two of these
68−goals.
79+An identity system has three goals: a name wants to be secure,
80+human-meaningful, and decentralized. A principle called "Zooko’s
81+triangle" says that a practical identity system can achieve any two of
82+these goals.
6983
70−We attack an unsolvable problem of this type by making tradeoffs.
71−Urbit's goals: to be secure, human-memorable, and eventually
72−decentralized. We sacrifice meaning (Urbit is not competing with the
73−DNS), and postpone decentralization. In turn, we get a simple system
74−that can actually be built.
84+The art of OS design is the art of using strategic tradeoffs to almost
85+solve unsolvable problems. Urbit's goals are to be secure,
86+human-*memorable*, and *eventually* decentralized. We sacrifice
87+meaning (Urbit is not competing with the DNS), and postpone
88+decentralization. These tradeoffs buy us a simple system that can
89+actually be built.
7590
7691### Comparison to existing identity layers
7792
@@ -83,16 +98,16 @@ addresses IP addresses (like `126.78.92.112`), domain names (like
8398`foobar.com`), and user identities (like `galen@tlon.io` or
8499`@galenwp`).
85100
86−Urbit (or more precisely, its Ames protocol) squashes all three of
87−these layers into one. At the network level, Urbit is a P2P overlay
88−network; your ship is your network address. It's also the name of
89−your server, and your secure digital pseudonym.
101+Urbit (or more precisely, its Ames protocol) squeezes all three layers
102+into one. At the network level, Urbit is a P2P overlay network; your
103+ship is your network address. It's also the name of your server.
104+Finally, it's your secure digital pseudonym. And we map your ship
105+name into the DNS, at `ship.urbit.org`.
90106
91−One way to use Urbit is as an identity for the Internet, which doesn't
92−have a standard system of secure authentication. Urbit has a
107+(One way to use Urbit is as an identity for the Internet, which
108+doesn't have a standard system of secure authentication. Urbit has a
93109single-signon API which lets any Web server accept Urbit logins, like
94−a normal social login -- but not captive to anyone's corporate
95−mainframe.
110+a normal social login -- but not captive to any central mainframe.)
96111
97112### Cryptographic ownership
98113
@@ -108,6 +123,16 @@ high-frequency, zero-friction transfers. Real estate transfers are
108123low frequency and high friction, so the "double spend" problem (which
109124mining solves) is much less pressing.
110125
126+Don't expect urbits to be tradeable on cryptocurrency exchanges. A
127+trade adds at least one signature to the ship's certificate, or two if
128+the parties don't trust each other and an intermediary is needed. A
129+bulky certificate isn't free, since it slows down new connections.
130+
131+This isn't a serious problem if urbits are treated like land. But it
132+prevents Urbit from being a competent currency. This is a feature,
133+not a bug. Urbit has no need to compete with Bitcoin or Ethereum,
134+and every reason not to.
135+
111136## Moons and comets
112137
113138In the general case, a ship is actually a 128-bit number. A full
@@ -117,10 +142,8 @@ table of ship classes:
1171428 bits galaxy router ~syd
11814316 bits star router ~delsym
11914432 bits planet human ~mighex-forfem
120−64 bits moon device
121−~dabnev-nisseb-nomlec-sormug
122−128 bits comet bot
123−~satnet-rinsyr-silsec-navhut--bacnec-todmeb-harwen-fabtev
145+64 bits moon device ~dabnev-nisseb-nomlec-sormug
146+128 bits comet bot ~satnet-rinsyr-silsec-navhut--bacnec-todmeb-harwen-fabtev
124147```
125148
126149Moons are for clients and connected devices: a laptop, a phone, a
@@ -147,7 +170,7 @@ consequence of scarce, individually owned identities. We're not
147170changing human nature, just creating the right economic incentives.
148171
149172Most forms of network abuse are "Sybil attacks": they rely on an
150−infinite supply of new identities. Scarcity makes reputation work.
173+infinite supply of fresh identities. Scarcity makes reputation work.
151174Spam is a business; if the cost of a new planet exceeds the amount of
152175money you can make by spamming from that planet until its reputation
153176is trashed, there will be no spam.
@@ -166,12 +189,12 @@ But we can't build one until we need one.
166189### Initial allocation and rationale
167190
168191In cryptocurrency terms, Urbit is "100% premined." Why? Three
169−reasons.
192+reasons.
170193
171194One, Urbit doesn't need mining. Two, Urbit is a much more ambitious
172195software project than Bitcoin or even Ethereum. To fund its own
173196development, the project needs to capture the potential value of its
174−own real estate.
197+own real estate.
175198
176199Three, most theories of property agree that anyone whoever creates or
177200discovers new property starts out by owning it. Because galaxies are
@@ -182,17 +205,17 @@ One, the more decentralized Urbit is, the more Urbit is worth. Two,
182205the only way for Urbit to fund its own development is to homestead its
183206own real estate.
184207
185−Urbit was made by Curtis Yarvin, who has distributed the 256 galaxies
186−as follows (allocation as of June 1, 2016):
208+Urbit was created by Curtis Yarvin, who has distributed the 256
209+galaxies as follows (allocation as of June 1, 2016):
187210
18821195, to the [Tlon Corporation](company). 50, to urbit.org, the future
189212community foundation. 40, to Tlon employees and their family members
190213(24 to Curtis, who started in 2002; 16 to everyone else, who started
191214in 2014). 34, to outside investors in Tlon. 37, to 33 other
192−individuals, who donated to the project, contributed code, won a
193−contest, or were otherwise in the right place at the right time.
215+individuals, who donated to the project, contributed code or services,
216+won a contest, or were just in the right place at the right time.
194217
195−What's important is that the whole system is unlikely to collapse back
218+What's critical is that the whole system is unlikely to collapse back
196219into a single landlord. This is why we've intentionally scattered
197220Urbit's ownership across a diverse set of entities.
198221
@@ -201,15 +224,14 @@ healthy ownership structure by punishing violators with reputation
201224cost. Address blocks should only split, never merge; galaxies and
202225stars should be owned by different parties; galaxies should be owned
203226by true individuals, not corporations. Urbit does not live up to
204−these ideals at present, but must progress toward them rather than
205−away.
227+these ideals at present, but must always progress toward them.
206228
207229### Federated services, adoption and escape
208230
209231Urbit is a peer-to-peer network. Urbits that live behind a firewall
210232or on a home network need "supernodes" to help them route packets.
211233The supernode is the parent. So a parent's work isn't done once it's
212−launched all its children.
234+launched all its children.
213235
214236There's no way to enforce this responsibility. So a star or planet
215237can be *adopted* by a new parent of the same class, letting it escape
@@ -224,18 +246,19 @@ these services are delivered by cooperating stars and galaxies. Bad
224246actors at this level should be rare.
225247
226248Especially when Urbit is young, the level of trust that a child places
227−in its parent is extremely high. The trust implied by automatic
228−kernel updates is essentially infinite. (Ideally we will be able to
229−freeze the Arvo kernel, like Nock, and turn off these totipotent
230−updates; but this will take years at least.)
249+in its parent is high. The trust implied by automatic kernel updates
250+is almost infinite. You can disable updates, but that's nowhere near
251+practical yet. (Ideally we will be able to freeze the Arvo kernel,
252+like Nock, and turn off kernel updates; but this will take years at
253+least.)
231254
232255### Code is law: seeing like a pattern language of great cities
233256
234−Constitutional innovation is extremely dangerous. Our vision of
235−digital governance isn't ours, but is synthesized as best we can from
236−the work of four great 20th-century thinkers: the legal scholar
237−Lawrence Lessig, the political scientist James C. Scott, the urbanist
238−Jane Jacobs and the architect Christopher Alexander.
257+Constitutional innovation is dangerous. Our vision of digital
258+governance isn't ours, but is synthesized as best we can from the work
259+of four great 20th-century thinkers: the legal scholar Lawrence
260+Lessig, the political scientist James C. Scott, the urbanist Jane
261+Jacobs and the architect Christopher Alexander.
239262
240263All decentralized computation systems rely to some extent on Lessig's
241264principle: "code is law." Where law uses human interpretation to
@@ -266,6 +289,7 @@ of larger states or countries.
266289We adapt Alexander's vision to a digital republic as the pattern that
267290*authority is proportional to property*. This pattern already has a
268291name in the cryptocurrency community, which calls it *proof of stake*.
292+Urbit's launch hierarchy is a sort of built-in proof of stake.
269293
270294Another governance pattern, a political cliche but no less valuable
271295for it, is the system of checks and balances. The address space of