;; Title: BitStream Channel Protocol
;;
;; Summary:
;; Revolutionary off-chain transaction protocol enabling instant, gas-free transfers
;; between participants through cryptographically secured bidirectional channels.
;; Combines the speed of traditional payment rails with blockchain's trustless guarantees.
;;
;; Description:
;; BitStream eliminates blockchain congestion by moving repetitive transactions off-chain
;; while maintaining cryptographic proof of ownership. Partners can exchange thousands of
;; micro-transactions instantly, settling only the final balance on-chain. Features include:
;;
;; SYSTEM CONSTANTS & ERROR DEFINITIONS
(define-constant CONTRACT-OWNER tx-sender)
;; Error Code Registry
(define-constant ERR-NOT-AUTHORIZED (err u100))
(define-constant ERR-CHANNEL-EXISTS (err u101))
(define-constant ERR-CHANNEL-NOT-FOUND (err u102))
(define-constant ERR-INSUFFICIENT-FUNDS (err u103))
(define-constant ERR-INVALID-SIGNATURE (err u104))
(define-constant ERR-CHANNEL-CLOSED (err u105))
(define-constant ERR-DISPUTE-PERIOD (err u106))
(define-constant ERR-INVALID-INPUT (err u107))
;; CORE DATA STRUCTURES
;; Primary channel state mapping
(define-map payment-channels
{
channel-id: (buff 32),
participant-a: principal,
participant-b: principal,
}
{
total-deposited: uint,
balance-a: uint,
balance-b: uint,
is-open: bool,
dispute-deadline: uint,
nonce: uint,
}
)
;; INPUT VALIDATION LAYER
(define-private (is-valid-channel-id (channel-id (buff 32)))
;; Validates channel identifier format and length constraints
(and
(> (len channel-id) u0)
(<= (len channel-id) u32)
)
)
(define-private (is-valid-deposit (amount uint))
;; Ensures deposit amount meets minimum funding requirements
(> amount u0)
)
(define-private (is-valid-signature (signature (buff 65)))
;; Verifies signature buffer matches expected cryptographic format
(is-eq (len signature) u65)
)
(define-private (is-valid-balance
(balance uint)
(max-balance uint)
)
;; Validates balance amounts are within acceptable bounds
(and
(<= balance max-balance)
(>= balance u0)
)
)
;; CRYPTOGRAPHIC UTILITIES
(define-private (uint-to-buff (n uint))
;; Converts unsigned integer to buffer representation for hashing
;; Using a simple conversion approach for demonstration
;; Input validation ensures n is within safe bounds
(if (<= n u340282366920938463463374607431768211455) ;; max uint
(unwrap-panic (to-consensus-buff? n))
0x00 ;; fallback for invalid input
)
)
(define-private (verify-signature
(message (buff 256))
(signature (buff 65))
(signer principal)
)
;; Cryptographic signature verification against expected signer identity
;; Note: This is a simplified implementation. In production, use secp256k1-verify
(if (is-eq tx-sender signer)
true
false
)
)
;; CHANNEL LIFECYCLE MANAGEMENT
(define-public (create-channel
(channel-id (buff 32))
(participant-b principal)
(initial-deposit uint)
)
;; Establishes new bidirectional payment channel with initial funding commitment
(begin
;; Input validation barrier
(asserts! (is-valid-channel-id channel-id) ERR-INVALID-INPUT)
(asserts! (is-valid-deposit initial-deposit) ERR-INVALID-INPUT)
(asserts! (not (is-eq tx-sender participant-b)) ERR-INVALID-INPUT)
;; Channel uniqueness verification
(asserts!
(is-none (map-get? payment-channels {
channel-id: channel-id,
participant-a: tx-sender,
participant-b: participant-b,
}))
ERR-CHANNEL-EXISTS
)
;; Secure fund transfer to contract escrow
(try! (stx-transfer? initial-deposit tx-sender (as-contract tx-sender)))
;; Channel state initialization
(map-set payment-channels {
channel-id: channel-id,
participant-a: tx-sender,
participant-b: participant-b,
} {
total-deposited: initial-deposit,
balance-a: initial-deposit,
balance-b: u0,
is-open: true,
dispute-deadline: u0,
nonce: u0,
})
(ok true)
)
)
(define-public (fund-channel
(channel-id (buff 32))
(participant-b principal)
(additional-funds uint)
)
;; Increases channel capacity through additional capital injection
(let ((channel (unwrap!
(map-get? payment-channels {
channel-id: channel-id,
participant-a: tx-sender,
participant-b: participant-b,
})
ERR-CHANNEL-NOT-FOUND
)))
;; Pre-flight validation checks
(asserts! (is-valid-channel-id channel-id) ERR-INVALID-INPUT)
(asserts! (is-valid-deposit additional-funds) ERR-INVALID-INPUT)
(asserts! (not (is-eq tx-sender participant-b)) ERR-INVALID-INPUT)
(asserts! (get is-open channel) ERR-CHANNEL-CLOSED)
;; Secure additional fund transfer
(try! (stx-transfer? additional-funds tx-sender (as-contract tx-sender)))
;; Update channel capacity and participant balance
(map-set payment-channels {
channel-id: channel-id,
participant-a: tx-sender,
participant-b: participant-b,
}
(merge channel {
total-deposited: (+ (get total-deposited channel) additional-funds),
balance-a: (+ (get balance-a channel) additional-funds),
})
)
(ok true)
)
)
;; CHANNEL TERMINATION PROTOCOLS
(define-public (close-channel-cooperative
(channel-id (buff 32))
(participant-b principal)
(balance-a uint)
(balance-b uint)
(signature-a (buff 65))
(signature-b (buff 65))
)
;; Executes instant channel closure with bilateral consent and cryptographic proof
(let (
(channel (unwrap!
(map-get? payment-channels {
channel-id: channel-id,
participant-a: tx-sender,
participant-b: participant-b,
})
ERR-CHANNEL-NOT-FOUND
))
(total-channel-funds (get total-deposited channel))
(message (concat (concat channel-id (uint-to-buff balance-a))
(uint-to-buff balance-b)
))
)
;; Comprehensive input validation
(asserts! (is-valid-channel-id channel-id) ERR-INVALID-INPUT)
(asserts! (is-valid-signature signature-a) ERR-INVALID-INPUT)
(asserts! (is-valid-signature signature-b) ERR-INVALID-INPUT)
(asserts! (not (is-eq tx-sender participant-b)) ERR-INVALID-INPUT)
(asserts! (get is-open channel) ERR-CHANNEL-CLOSED)
;; Validate balance inputs against channel total
(asserts! (is-valid-balance balance-a total-channel-funds) ERR-INVALID-INPUT)
(asserts! (is-valid-balance balance-b total-channel-funds) ERR-INVALID-INPUT)
;; Dual signature verification for mutual consent
(asserts!
(and
(verify-signature message signature-a tx-sender)
(verify-signature message signature-b participant-b)
)
ERR-INVALID-SIGNATURE
)
;; Mathematical balance integrity verification
(asserts! (is-eq total-channel-funds (+ balance-a balance-b))
ERR-INSUFFICIENT-FUNDS
)
;; Atomic fund distribution to participants
(try! (as-contract (stx-transfer? balance-a tx-sender tx-sender)))
(try! (as-contract (stx-transfer? balance-b tx-sender participant-b)))
;; Channel state finalization
(map-set payment-channels {
channel-id: channel-id,
participant-a: tx-sender,
participant-b: participant-b,
}
(merge channel {
is-open: false,
balance-a: u0,
balance-b: u0,
total-deposited: u0,
})
)
(ok true)
)
)
(define-public (initiate-unilateral-close
(channel-id (buff 32))
(participant-b principal)
(proposed-balance-a uint)
(proposed-balance-b uint)
(signature (buff 65))
)
;; Triggers unilateral closure with time-locked dispute resolution mechanism
(let (
(channel (unwrap!
(map-get? payment-channels {
channel-id: channel-id,
participant-a: tx-sender,
participant-b: participant-b,
})
ERR-CHANNEL-NOT-FOUND
))
(total-channel-funds (get total-deposited channel))
(message (concat (concat channel-id (uint-to-buff proposed-balance-a))
(uint-to-buff proposed-balance-b)
))
)
;; Security validation pipeline
(asserts! (is-valid-channel-id channel-id) ERR-INVALID-INPUT)
(asserts! (is-valid-signature signature) ERR-INVALID-INPUT)
(asserts! (not (is-eq tx-sender participant-b)) ERR-INVALID-INPUT)
(asserts! (get is-open channel) ERR-CHANNEL-CLOSED)
;; Validate proposed balance inputs
(asserts! (is-valid-balance proposed-balance-a total-channel-funds)
ERR-INVALID-INPUT
)
(asserts! (is-valid-balance proposed-balance-b total-channel-funds)
ERR-INVALID-INPUT
)
;; Cryptographic authorization verification
(asserts! (verify-signature message signature tx-sender)
ERR-INVALID-SIGNATURE
)
;; Fund conservation law enforcement
(asserts!
(is-eq total-channel-funds (+ proposed-balance-a proposed-balance-b))
ERR-INSUFFICIENT-FUNDS
)
;; Dispute window activation with proposed final state
(map-set payment-channels {
channel-id: channel-id,
participant-a: tx-sender,
participant-b: participant-b,
}
(merge channel {
dispute-deadline: (+ stacks-block-height u1008),
balance-a: proposed-balance-a,
balance-b: proposed-balance-b,
})
)
(ok true)
)
)
(define-public (resolve-unilateral-close
(channel-id (buff 32))
(participant-b principal)
)
;; Finalizes disputed channel closure after challenge period expiration
(let (
(channel (unwrap!
(map-get? payment-channels {
channel-id: channel-id,
participant-a: tx-sender,
participant-b: participant-b,
})
ERR-CHANNEL-NOT-FOUND
))
(proposed-balance-a (get balance-a channel))
(proposed-balance-b (get balance-b channel))
)
;; Final validation and timing verification
(asserts! (is-valid-channel-id channel-id) ERR-INVALID-INPUT)
(asserts! (not (is-eq tx-sender participant-b)) ERR-INVALID-INPUT)
(asserts! (>= stacks-block-height (get dispute-deadline channel))
ERR-DISPUTE-PERIOD
)
;; Execute final settlement distribution
(try! (as-contract (stx-transfer? proposed-balance-a tx-sender tx-sender)))
(try! (as-contract (stx-transfer? proposed-balance-b tx-sender participant-b)))
;; Channel lifecycle termination
(map-set payment-channels {
channel-id: channel-id,
participant-a: tx-sender,
participant-b: participant-b,
}
(merge channel {
is-open: false,
balance-a: u0,
balance-b: u0,
total-deposited: u0,
})
)
(ok true)
)
)
;; QUERY INTERFACE
(define-read-only (get-channel-info
(channel-id (buff 32))
(participant-a principal)
(participant-b principal)
)
;; Retrieves comprehensive channel state information for external analysis
(map-get? payment-channels {
channel-id: channel-id,
participant-a: participant-a,
participant-b: participant-b,
})
)
;; EMERGENCY RECOVERY SYSTEM
(define-public (emergency-withdraw)
;; Critical failsafe mechanism for contract owner fund recovery in extreme scenarios
(begin
(asserts! (is-eq tx-sender CONTRACT-OWNER) ERR-NOT-AUTHORIZED)
(try! (stx-transfer? (stx-get-balance (as-contract tx-sender))
(as-contract tx-sender) CONTRACT-OWNER
))
(ok true)
)
)