Install Virtual App Protocol
Last updated
Last updated
This is the Install Virtual App Protocol.
Three users run the protocol. They are designated as initiating
, responding
, and intermediary
. The first two parties are the users wishing to interact together in a virtual app, who do not necessarily have a ledger channel between them. It is required that initiating
and intermediary
have a ledger channel together, and that responding
and intermediary
have a ledger channel together.
InstallVirtualAppParams
typeThese fields are not included in InstallVirtualAppParams
but are computed from existing information known to a user.
{initiating,responding,intermediary}
, together with the target app sequence number, are used to derive the app-specific signing keys. signingKeys[0]
is the intermediary signing key, while signingKeys[1:2]
are the signing keys used by initiating
and responding
, sorted lexicographically by public key.
A commitment to call ETHVirtualAppAgreement::delegateTarget
with an Agreement
argument with the following fields
A commitment to call ETHVirtualAppAgreement::delegateTarget
terms
:limit
is explicitly ignored by the contract, while assetType, token == 0, 0
means ETH.
The protocol produces a commitment to call virtualAppSetState
with the initial state. Note that intermediary
produces a "type 2" signature while the others produce a "type 1" signature. This ensures that the intermediary's signature can be reused for calling virtualAppSetState
with other app state hash values, i.e., that the intermediary does not need to be part of the update-virtual-app protocol.
The signatures s5
and s7
are the signatures of initiating
and responding
respectively on d1
while the signature s6
is the signature of intermediary
on d2
.
Field
type
description
initiatingXpub
xpub
xpub of initiating
respondingXpub
xpub
xpub of responding
intermediaryXpub
xpub
xpub of intermediary
defaultTimeout
uint256
appInterface
AppInterface
initialState
JSON
Encoded initial app state
initiatingBalanceDecrement
uint256
initiating
's deposit into the installed application
respondingBalanceDecrement
uint256
responding
's deposit into the installed application
expiry
uint256
Not implemented in machine yet
Field
type
description
multisig1Address
address
State deposit holder for the channel between initiating
and intermediary
multisig2Address
address
State deposit holder for the channel between intermediary
and responding
signingKeys
address[]
See below
Field
type
description
registry
address
From network context
terms
Terms
See below
expiry
address
expiry
appIdentityHash
bytes32
Hash of appIdentity of target virtual app
capitalProvided
uint256
aliceBalanceDecrement
+ bobBalanceDecrement
beneficiaries
address[2]
[initiatingAddress, intermediaryAddress]
Field
type
description
registry
address
From network context
terms
Terms
See below
expiry
address
expiry
appIdentityHash
bytes32
Hash of appIdentity of target virtual app
capitalProvided
uint256
aliceBalanceDecrement
+ bobBalanceDecrement
beneficiaries
address[2]
[intermediaryAddress, respondingAddress]
Field
type
description
assetType
uint8
0
token
address
address(0)
limit
uint256
0
Field
Type
Description
protocol
string
"install-virtual-app"
multisig
address
multisig1Address
params
InstallVirtualAppParams
fromAddress
address
initiatingAddress
toAddress
address
intermediaryAddress
seq
number
1
signature1
signature
The S1 signature
signature2
signature
The S5 signature
Field
Description
protocol
"install-virtual-app"
multisig
multisig2Address
params
InstallVirtualAppParams
fromAddress
intermediaryAddress
toAddress
respondingAddress
seq
2
signature1
The S5 signature (forwarded).
signature2
The S3 signature
Field
Description
protocol
"install-virtual-app"
multisig
multisig2Address
fromAddress
respondingAddress
toAddress
intermediaryAddress
seq
3
signature1
The S4 signature.
signature2
The S7 signature.
Field
Description
protocol
"install-virtual-app"
multisig
multisig2Address
fromAddress
intermediaryAddress
toAddress
respondingAddress
seq
4
signature1
The S6 signature.
Field
Description
protocol
"install-virtual-app"
multisig
multisig1Address
fromAddress
intermediaryAddress
toAddress
initiatingAddress
seq
5
signature1
The S6 signature.
signature2
The S2 signature.
signature3
The S7 signature.
Signature
Commitment
Signed By
s1
leftETHVirtualAppAgreement
A
s2
leftETHVirtualAppAgreement
I
s3
rightETHVirtualAppAgreement
I
s4
rightETHVirtualAppAgreement
B
s5
targetVirtualAppSetState
A
s6
targetVirtualAppSetState
I
s7
targetVirtualAppSetState
B
Message
Signatures
m1
s1, s5
m2
s5, s3
m3
s4, s7
m4
s6
m5
s6, s2, s7