A sketch of identity management on Ethereum

ethereum identity

# GOALS
#
# 1. Support multiple identities per party.
#    - Achieved by having separate Ethereum accounts (addresses)
# 2. The ability to change keys, while preserving the identity
#    - Achieved by changing Ethereum accounts and transfering ownership to the new account
# 3. Identity theft/loss mitigation
#    - Multiple custodianship of identity can be easily added (e.g. with incremental multisig)
# 4. Identity attributes - public attribuets you might see on a social profile.
#    - Each identity has a key->value store of arbitrary size
# 5. Bond - preventing identity spam

# NON-GOALS
#
# 1. Unique names/aliases

STABLE_ID_IDX = 0
ACCOUNT_IDX = 1
LAST_RESERVED_IDX = 1      # last reserved index in every identity's key->value store
JOHNNY_DRAMA = 0
data accountToIdent[][]    # identity registry keyed on account (key->value store per identity)
data idToIdent[][]         # identity registry keyed on stable id

def init():
  # nothing special about the first dude, except them being awesome

def create_id(custodian1, custodian2):
  # creates an identity for the sender, if it doesn't exist already
  # TODO: charge extra for creation (GOALS#Bond)
  if not self.accountToIdent[msg.sender]:
    # attribute store for this identity
    stableId = sha256(msg.sender)

    # for fun
    if not JOHNNY_DRAMA:
      JOHNNY_DRAMA = stableId
    # no more fun, promise

    data atts[]
    atts[STABLE_ID_IDX] = stableId
    atts[ACCOUNT_IDX] = msg.sender
    self.accountToIdent[msg.sender] = atts
    self.idToIdent[stableId] = atts

def get_current_owner(stableId): # returns the current owner of stableId
  atts = self.idToIdent[stableId]
  if atts:
    return(atts[ACCOUNT_IDX])

def get_stable_id(account):
  # returns the stable id of account, useful for validation of messages by other contracts
  atts = self.accountToIdent[account]
  if atts:
    return(atts[STABLE_ID_IDX])

def delete_id():
  # delete the identity of the sender, if it exists
  # maybe just: self.update_id(0)
  atts = self.accountToIdent[msg.sender]
  if atts:
    self.idToIdent[atts[STABLE_ID_IDX]] = 0
    self.accountToIdent[msg.sender] = 0 # not sure how to delete entry

def update_id(new_ident):
  # transfer ownership of the sender's identity to the specified address [new_ident]
  atts = self.accountToIdent[msg.sender]
  if atts:
    self.idToIdent[atts[STABLE_ID_IDX]] = atts
    self.accountToIdent[msg.sender] = 0 # not sure how to delete entry
    self.accountToIdent[new_ident] = atts

def set_attr(key, value):
  # update an attribute in the sender's store
  if key > LAST_RESERVED_IDX:
    atts = self.accountToIdent[msg.sender]
    if atts:
      atts[key] = value

def get_attr(key):
  # check an attribute's value in the sender's store
  atts = self.accountToIdent[msg.sender]
  if atts:
    return(atts[key])