From d3eb59691d01507c269f698ad3eea794c3cc615f Mon Sep 17 00:00:00 2001
From: nicholaspai <npai.nyc@gmail.com>
Date: Tue, 15 Mar 2022 10:47:42 -0400
Subject: [PATCH 1/4] improve: Change time-related variables to type uint64

---
 contracts/HubPool.sol            | 28 ++++++++++++++++------------
 contracts/HubPoolInterface.sol   |  2 +-
 contracts/SpokePool.sol          | 16 ++++++++--------
 contracts/SpokePoolInterface.sol |  4 ++--
 4 files changed, 27 insertions(+), 23 deletions(-)

diff --git a/contracts/HubPool.sol b/contracts/HubPool.sol
index c10d7fb4a..f777645a7 100644
--- a/contracts/HubPool.sol
+++ b/contracts/HubPool.sol
@@ -64,7 +64,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
         // of leaves are executed, a new root bundle can be proposed
         uint8 unclaimedPoolRebalanceLeafCount;
         // When root bundle challenge period passes and this root bundle becomes executable.
-        uint32 requestExpirationTimestamp;
+        uint64 requestExpirationTimestamp;
     }
 
     // Only one root bundle can be stored at a time. Once all pool rebalance leaves are executed, a new proposal
@@ -84,7 +84,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
         // True if accepting new LP's.
         bool isEnabled;
         // Timestamp of last LP fee update.
-        uint32 lastLpFeeUpdate;
+        uint64 lastLpFeeUpdate;
         // Number of LP funds sent via pool rebalances to SpokePools and are expected to be sent
         // back later.
         int256 utilizedReserves;
@@ -137,7 +137,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
 
     // Each root bundle proposal must stay in liveness for this period of time before it can be considered finalized.
     // It can be disputed only during this period of time. Defaults to 2 hours, like the rest of the UMA ecosystem.
-    uint32 public liveness = 7200;
+    uint64 public liveness = 7200;
 
     event Paused(bool indexed isPaused);
 
@@ -185,7 +185,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
     );
 
     event ProposeRootBundle(
-        uint32 requestExpirationTimestamp,
+        uint64 requestExpirationTimestamp,
         uint64 unclaimedPoolRebalanceLeafCount,
         uint256[] bundleEvaluationBlockNumbers,
         bytes32 indexed poolRebalanceRoot,
@@ -334,7 +334,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
      * @notice Sets root bundle proposal liveness period. Callable only by owner.
      * @param newLiveness New liveness period.
      */
-    function setLiveness(uint32 newLiveness) public override onlyOwner {
+    function setLiveness(uint64 newLiveness) public override onlyOwner {
         require(newLiveness > 10 minutes, "Liveness too short");
         liveness = newLiveness;
         emit LivenessSet(newLiveness);
@@ -415,7 +415,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
             pooledTokens[l1Token].lpToken = lpTokenFactory.createLpToken(l1Token);
 
         pooledTokens[l1Token].isEnabled = true;
-        pooledTokens[l1Token].lastLpFeeUpdate = uint32(getCurrentTime());
+        pooledTokens[l1Token].lastLpFeeUpdate = uint64(getCurrentTime());
 
         emit L1TokenEnabledForLiquidityProvision(l1Token, pooledTokens[l1Token].lpToken);
     }
@@ -561,7 +561,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
         // technically valid but not useful. This could also potentially be enforced at the UMIP-level.
         require(poolRebalanceLeafCount > 0, "Bundle must have at least 1 leaf");
 
-        uint32 requestExpirationTimestamp = uint32(getCurrentTime()) + liveness;
+        uint64 requestExpirationTimestamp = uint64(getCurrentTime()) + liveness;
 
         delete rootBundleProposal; // Only one bundle of roots can be executed at a time.
 
@@ -665,7 +665,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
      * optimistic oracle to be adjudicated. Can only be called within the liveness period of the current proposal.
      */
     function disputeRootBundle() public nonReentrant zeroOptimisticOracleApproval {
-        uint32 currentTime = uint32(getCurrentTime());
+        uint64 currentTime = uint64(getCurrentTime());
         require(currentTime <= rootBundleProposal.requestExpirationTimestamp, "Request passed liveness");
 
         // Request price from OO and dispute it.
@@ -686,7 +686,9 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
         try
             optimisticOracle.requestAndProposePriceFor(
                 identifier,
-                currentTime,
+                uint32(currentTime), // Note: Because the skinny OO interface requires a uint32 value here, this code
+                // will be unreliable beginning around the year 2106 because casting the time to a uint32 will overflow
+                // to 0 at that point.
                 requestAncillaryData,
                 bondToken,
                 // Set reward to 0, since we'll settle proposer reward payouts directly from this contract after a root
@@ -711,6 +713,8 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
         }
 
         // Dispute the request that we just sent.
+        // Note: We might as well cast the expiration time similarly to
+        // uint32 so at least if the time rolls over to 0 after the year 2106, proposals can still expire.
         SkinnyOptimisticOracleInterface.Request memory ooPriceRequest = SkinnyOptimisticOracleInterface.Request({
             proposer: rootBundleProposal.proposer,
             disputer: address(0),
@@ -718,7 +722,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
             settled: false,
             proposedPrice: int256(1e18),
             resolvedPrice: 0,
-            expirationTime: currentTime + liveness,
+            expirationTime: uint256(uint32(currentTime + liveness)),
             reward: 0,
             finalFee: finalFee,
             bond: bondAmount - finalFee,
@@ -729,7 +733,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
         bondToken.safeIncreaseAllowance(address(optimisticOracle), bondAmount);
         optimisticOracle.disputePriceFor(
             identifier,
-            currentTime,
+            uint32(currentTime),
             requestAncillaryData,
             ooPriceRequest,
             msg.sender,
@@ -936,7 +940,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
     function _updateAccumulatedLpFees(PooledToken storage pooledToken) internal {
         uint256 accumulatedFees = _getAccumulatedFees(pooledToken.undistributedLpFees, pooledToken.lastLpFeeUpdate);
         pooledToken.undistributedLpFees -= accumulatedFees;
-        pooledToken.lastLpFeeUpdate = uint32(getCurrentTime());
+        pooledToken.lastLpFeeUpdate = uint64(getCurrentTime());
     }
 
     // Calculate the unallocated accumulatedFees from the last time the contract was called.
diff --git a/contracts/HubPoolInterface.sol b/contracts/HubPoolInterface.sol
index a13f61193..9edc7a089 100644
--- a/contracts/HubPoolInterface.sol
+++ b/contracts/HubPoolInterface.sol
@@ -44,7 +44,7 @@ interface HubPoolInterface {
 
     function setBond(IERC20 newBondToken, uint256 newBondAmount) external;
 
-    function setLiveness(uint32 newLiveness) external;
+    function setLiveness(uint64 newLiveness) external;
 
     function setIdentifier(bytes32 newIdentifier) external;
 
diff --git a/contracts/SpokePool.sol b/contracts/SpokePool.sol
index e31c73412..29dc63a71 100644
--- a/contracts/SpokePool.sol
+++ b/contracts/SpokePool.sol
@@ -46,7 +46,7 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
 
     // Any deposit quote times greater than or less than this value to the current contract time is blocked. Forces
     // caller to use an approximately "current" realized fee. Defaults to 10 minutes.
-    uint32 public depositQuoteTimeBuffer = 600;
+    uint64 public depositQuoteTimeBuffer = 600;
 
     // Count of deposits is used to construct a unique deposit identifier for this spoke pool.
     uint32 public numberOfDeposits;
@@ -82,14 +82,14 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
     event SetXDomainAdmin(address indexed newAdmin);
     event SetHubPool(address indexed newHubPool);
     event EnabledDepositRoute(address indexed originToken, uint256 indexed destinationChainId, bool enabled);
-    event SetDepositQuoteTimeBuffer(uint32 newBuffer);
+    event SetDepositQuoteTimeBuffer(uint64 newBuffer);
     event FundsDeposited(
         uint256 amount,
         uint256 originChainId,
         uint256 destinationChainId,
         uint64 relayerFeePct,
         uint32 indexed depositId,
-        uint32 quoteTimestamp,
+        uint64 quoteTimestamp,
         address indexed originToken,
         address recipient,
         address indexed depositor
@@ -211,7 +211,7 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
      * @notice Change allowance for deposit quote time to differ from current block time. Callable by admin only.
      * @param newDepositQuoteTimeBuffer New quote time buffer.
      */
-    function setDepositQuoteTimeBuffer(uint32 newDepositQuoteTimeBuffer) public override onlyAdmin {
+    function setDepositQuoteTimeBuffer(uint64 newDepositQuoteTimeBuffer) public override onlyAdmin {
         depositQuoteTimeBuffer = newDepositQuoteTimeBuffer;
         emit SetDepositQuoteTimeBuffer(newDepositQuoteTimeBuffer);
     }
@@ -270,7 +270,7 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
         uint256 amount,
         uint256 destinationChainId,
         uint64 relayerFeePct,
-        uint32 quoteTimestamp
+        uint64 quoteTimestamp
     ) public payable override onlyEnabledRoute(originToken, destinationChainId) nonReentrant {
         // We limit the relay fees to prevent the user spending all their funds on fees.
         require(relayerFeePct < 0.5e18, "invalid relayer fee");
@@ -280,8 +280,8 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
         // Note also that quoteTimestamp cannot be less than the buffer otherwise the following arithmetic can result
         // in underflow. This isn't a problem as the deposit will revert, but the error might be unexpected for clients.
         require(
-            getCurrentTime() >= quoteTimestamp - depositQuoteTimeBuffer &&
-                getCurrentTime() <= quoteTimestamp + depositQuoteTimeBuffer,
+            uint64(getCurrentTime()) >= quoteTimestamp - depositQuoteTimeBuffer &&
+                uint64(getCurrentTime()) <= quoteTimestamp + depositQuoteTimeBuffer,
             "invalid quote time"
         );
         // If the address of the origin token is a WETH contract and there is a msg.value with the transaction
@@ -822,7 +822,7 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
         uint256 destinationChainId,
         uint64 relayerFeePct,
         uint32 depositId,
-        uint32 quoteTimestamp,
+        uint64 quoteTimestamp,
         address originToken,
         address recipient,
         address depositor
diff --git a/contracts/SpokePoolInterface.sol b/contracts/SpokePoolInterface.sol
index 5f49b0ca8..82850c11d 100644
--- a/contracts/SpokePoolInterface.sol
+++ b/contracts/SpokePoolInterface.sol
@@ -58,7 +58,7 @@ interface SpokePoolInterface {
         bool enable
     ) external;
 
-    function setDepositQuoteTimeBuffer(uint32 buffer) external;
+    function setDepositQuoteTimeBuffer(uint64 buffer) external;
 
     function relayRootBundle(bytes32 relayerRefundRoot, bytes32 slowRelayRoot) external;
 
@@ -70,7 +70,7 @@ interface SpokePoolInterface {
         uint256 amount,
         uint256 destinationChainId,
         uint64 relayerFeePct,
-        uint32 quoteTimestamp
+        uint64 quoteTimestamp
     ) external payable;
 
     function speedUpDeposit(

From 58d224ae62661b0b35810a21c9c39286ff9d9c20 Mon Sep 17 00:00:00 2001
From: nicholaspai <npai.nyc@gmail.com>
Date: Tue, 15 Mar 2022 10:52:07 -0400
Subject: [PATCH 2/4] Update HubPool.sol

---
 contracts/HubPool.sol | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/contracts/HubPool.sol b/contracts/HubPool.sol
index f777645a7..62fc3db69 100644
--- a/contracts/HubPool.sol
+++ b/contracts/HubPool.sol
@@ -33,6 +33,11 @@ import "@openzeppelin/contracts/utils/Address.sol";
  * responsible for publishing relayer refund and slow relay merkle roots to SpokePools.
  * @notice This contract is meant to act as the cross chain administrator and owner of all L2 spoke pools, so all
  * governance actions and pool rebalances originate from here and bridge instructions to L2s.
+ * @dev This contract should be deprecated by the year 2106, at which point uint32 timestamps will roll over. This is
+ * an issue for this contract because the SkinnyOptimisticOracleInterface expects request timestamps to be uint32,
+ * which will create uncertain behavior for disputes sent after that year. In all likelihood, the SkinnyOptimisticOracle
+ * will be deprecated by 2106 and upgraded to an interface that can handle at least uint64 timestamps, and this
+ * contract can be upgraded to handle that new interface.
  */
 contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
     using SafeERC20 for IERC20;

From 2d6b1d388c4ba797674ec07904e4245ca3fbfb6a Mon Sep 17 00:00:00 2001
From: nicholaspai <npai.nyc@gmail.com>
Date: Tue, 15 Mar 2022 12:07:34 -0400
Subject: [PATCH 3/4] Update HubPool.sol

---
 contracts/HubPool.sol | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/contracts/HubPool.sol b/contracts/HubPool.sol
index 62fc3db69..aab37b634 100644
--- a/contracts/HubPool.sol
+++ b/contracts/HubPool.sol
@@ -34,10 +34,9 @@ import "@openzeppelin/contracts/utils/Address.sol";
  * @notice This contract is meant to act as the cross chain administrator and owner of all L2 spoke pools, so all
  * governance actions and pool rebalances originate from here and bridge instructions to L2s.
  * @dev This contract should be deprecated by the year 2106, at which point uint32 timestamps will roll over. This is
- * an issue for this contract because the SkinnyOptimisticOracleInterface expects request timestamps to be uint32,
- * which will create uncertain behavior for disputes sent after that year. In all likelihood, the SkinnyOptimisticOracle
- * will be deprecated by 2106 and upgraded to an interface that can handle at least uint64 timestamps, and this
- * contract can be upgraded to handle that new interface.
+ * an issue for this contract because fee calculations will become bizarre when multiplying by negative time deltas.
+ * Before this date, this contract should be paused from accepting new root bundles and all LP tokens should be
+ * disabled by the admin.
  */
 contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
     using SafeERC20 for IERC20;

From 2f59388906346780e729f2b879b643941ea314c9 Mon Sep 17 00:00:00 2001
From: nicholaspai <npai.nyc@gmail.com>
Date: Tue, 15 Mar 2022 12:07:46 -0400
Subject: [PATCH 4/4] Revert "improve: Change time-related variables to type
 uint64"

This reverts commit d3eb59691d01507c269f698ad3eea794c3cc615f.
---
 contracts/HubPool.sol            | 28 ++++++++++++----------------
 contracts/HubPoolInterface.sol   |  2 +-
 contracts/SpokePool.sol          | 16 ++++++++--------
 contracts/SpokePoolInterface.sol |  4 ++--
 4 files changed, 23 insertions(+), 27 deletions(-)

diff --git a/contracts/HubPool.sol b/contracts/HubPool.sol
index aab37b634..b9c59bbfa 100644
--- a/contracts/HubPool.sol
+++ b/contracts/HubPool.sol
@@ -68,7 +68,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
         // of leaves are executed, a new root bundle can be proposed
         uint8 unclaimedPoolRebalanceLeafCount;
         // When root bundle challenge period passes and this root bundle becomes executable.
-        uint64 requestExpirationTimestamp;
+        uint32 requestExpirationTimestamp;
     }
 
     // Only one root bundle can be stored at a time. Once all pool rebalance leaves are executed, a new proposal
@@ -88,7 +88,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
         // True if accepting new LP's.
         bool isEnabled;
         // Timestamp of last LP fee update.
-        uint64 lastLpFeeUpdate;
+        uint32 lastLpFeeUpdate;
         // Number of LP funds sent via pool rebalances to SpokePools and are expected to be sent
         // back later.
         int256 utilizedReserves;
@@ -141,7 +141,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
 
     // Each root bundle proposal must stay in liveness for this period of time before it can be considered finalized.
     // It can be disputed only during this period of time. Defaults to 2 hours, like the rest of the UMA ecosystem.
-    uint64 public liveness = 7200;
+    uint32 public liveness = 7200;
 
     event Paused(bool indexed isPaused);
 
@@ -189,7 +189,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
     );
 
     event ProposeRootBundle(
-        uint64 requestExpirationTimestamp,
+        uint32 requestExpirationTimestamp,
         uint64 unclaimedPoolRebalanceLeafCount,
         uint256[] bundleEvaluationBlockNumbers,
         bytes32 indexed poolRebalanceRoot,
@@ -338,7 +338,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
      * @notice Sets root bundle proposal liveness period. Callable only by owner.
      * @param newLiveness New liveness period.
      */
-    function setLiveness(uint64 newLiveness) public override onlyOwner {
+    function setLiveness(uint32 newLiveness) public override onlyOwner {
         require(newLiveness > 10 minutes, "Liveness too short");
         liveness = newLiveness;
         emit LivenessSet(newLiveness);
@@ -419,7 +419,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
             pooledTokens[l1Token].lpToken = lpTokenFactory.createLpToken(l1Token);
 
         pooledTokens[l1Token].isEnabled = true;
-        pooledTokens[l1Token].lastLpFeeUpdate = uint64(getCurrentTime());
+        pooledTokens[l1Token].lastLpFeeUpdate = uint32(getCurrentTime());
 
         emit L1TokenEnabledForLiquidityProvision(l1Token, pooledTokens[l1Token].lpToken);
     }
@@ -565,7 +565,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
         // technically valid but not useful. This could also potentially be enforced at the UMIP-level.
         require(poolRebalanceLeafCount > 0, "Bundle must have at least 1 leaf");
 
-        uint64 requestExpirationTimestamp = uint64(getCurrentTime()) + liveness;
+        uint32 requestExpirationTimestamp = uint32(getCurrentTime()) + liveness;
 
         delete rootBundleProposal; // Only one bundle of roots can be executed at a time.
 
@@ -669,7 +669,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
      * optimistic oracle to be adjudicated. Can only be called within the liveness period of the current proposal.
      */
     function disputeRootBundle() public nonReentrant zeroOptimisticOracleApproval {
-        uint64 currentTime = uint64(getCurrentTime());
+        uint32 currentTime = uint32(getCurrentTime());
         require(currentTime <= rootBundleProposal.requestExpirationTimestamp, "Request passed liveness");
 
         // Request price from OO and dispute it.
@@ -690,9 +690,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
         try
             optimisticOracle.requestAndProposePriceFor(
                 identifier,
-                uint32(currentTime), // Note: Because the skinny OO interface requires a uint32 value here, this code
-                // will be unreliable beginning around the year 2106 because casting the time to a uint32 will overflow
-                // to 0 at that point.
+                currentTime,
                 requestAncillaryData,
                 bondToken,
                 // Set reward to 0, since we'll settle proposer reward payouts directly from this contract after a root
@@ -717,8 +715,6 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
         }
 
         // Dispute the request that we just sent.
-        // Note: We might as well cast the expiration time similarly to
-        // uint32 so at least if the time rolls over to 0 after the year 2106, proposals can still expire.
         SkinnyOptimisticOracleInterface.Request memory ooPriceRequest = SkinnyOptimisticOracleInterface.Request({
             proposer: rootBundleProposal.proposer,
             disputer: address(0),
@@ -726,7 +722,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
             settled: false,
             proposedPrice: int256(1e18),
             resolvedPrice: 0,
-            expirationTime: uint256(uint32(currentTime + liveness)),
+            expirationTime: currentTime + liveness,
             reward: 0,
             finalFee: finalFee,
             bond: bondAmount - finalFee,
@@ -737,7 +733,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
         bondToken.safeIncreaseAllowance(address(optimisticOracle), bondAmount);
         optimisticOracle.disputePriceFor(
             identifier,
-            uint32(currentTime),
+            currentTime,
             requestAncillaryData,
             ooPriceRequest,
             msg.sender,
@@ -944,7 +940,7 @@ contract HubPool is HubPoolInterface, Testable, Lockable, MultiCaller, Ownable {
     function _updateAccumulatedLpFees(PooledToken storage pooledToken) internal {
         uint256 accumulatedFees = _getAccumulatedFees(pooledToken.undistributedLpFees, pooledToken.lastLpFeeUpdate);
         pooledToken.undistributedLpFees -= accumulatedFees;
-        pooledToken.lastLpFeeUpdate = uint64(getCurrentTime());
+        pooledToken.lastLpFeeUpdate = uint32(getCurrentTime());
     }
 
     // Calculate the unallocated accumulatedFees from the last time the contract was called.
diff --git a/contracts/HubPoolInterface.sol b/contracts/HubPoolInterface.sol
index 9edc7a089..a13f61193 100644
--- a/contracts/HubPoolInterface.sol
+++ b/contracts/HubPoolInterface.sol
@@ -44,7 +44,7 @@ interface HubPoolInterface {
 
     function setBond(IERC20 newBondToken, uint256 newBondAmount) external;
 
-    function setLiveness(uint64 newLiveness) external;
+    function setLiveness(uint32 newLiveness) external;
 
     function setIdentifier(bytes32 newIdentifier) external;
 
diff --git a/contracts/SpokePool.sol b/contracts/SpokePool.sol
index 29dc63a71..e31c73412 100644
--- a/contracts/SpokePool.sol
+++ b/contracts/SpokePool.sol
@@ -46,7 +46,7 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
 
     // Any deposit quote times greater than or less than this value to the current contract time is blocked. Forces
     // caller to use an approximately "current" realized fee. Defaults to 10 minutes.
-    uint64 public depositQuoteTimeBuffer = 600;
+    uint32 public depositQuoteTimeBuffer = 600;
 
     // Count of deposits is used to construct a unique deposit identifier for this spoke pool.
     uint32 public numberOfDeposits;
@@ -82,14 +82,14 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
     event SetXDomainAdmin(address indexed newAdmin);
     event SetHubPool(address indexed newHubPool);
     event EnabledDepositRoute(address indexed originToken, uint256 indexed destinationChainId, bool enabled);
-    event SetDepositQuoteTimeBuffer(uint64 newBuffer);
+    event SetDepositQuoteTimeBuffer(uint32 newBuffer);
     event FundsDeposited(
         uint256 amount,
         uint256 originChainId,
         uint256 destinationChainId,
         uint64 relayerFeePct,
         uint32 indexed depositId,
-        uint64 quoteTimestamp,
+        uint32 quoteTimestamp,
         address indexed originToken,
         address recipient,
         address indexed depositor
@@ -211,7 +211,7 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
      * @notice Change allowance for deposit quote time to differ from current block time. Callable by admin only.
      * @param newDepositQuoteTimeBuffer New quote time buffer.
      */
-    function setDepositQuoteTimeBuffer(uint64 newDepositQuoteTimeBuffer) public override onlyAdmin {
+    function setDepositQuoteTimeBuffer(uint32 newDepositQuoteTimeBuffer) public override onlyAdmin {
         depositQuoteTimeBuffer = newDepositQuoteTimeBuffer;
         emit SetDepositQuoteTimeBuffer(newDepositQuoteTimeBuffer);
     }
@@ -270,7 +270,7 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
         uint256 amount,
         uint256 destinationChainId,
         uint64 relayerFeePct,
-        uint64 quoteTimestamp
+        uint32 quoteTimestamp
     ) public payable override onlyEnabledRoute(originToken, destinationChainId) nonReentrant {
         // We limit the relay fees to prevent the user spending all their funds on fees.
         require(relayerFeePct < 0.5e18, "invalid relayer fee");
@@ -280,8 +280,8 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
         // Note also that quoteTimestamp cannot be less than the buffer otherwise the following arithmetic can result
         // in underflow. This isn't a problem as the deposit will revert, but the error might be unexpected for clients.
         require(
-            uint64(getCurrentTime()) >= quoteTimestamp - depositQuoteTimeBuffer &&
-                uint64(getCurrentTime()) <= quoteTimestamp + depositQuoteTimeBuffer,
+            getCurrentTime() >= quoteTimestamp - depositQuoteTimeBuffer &&
+                getCurrentTime() <= quoteTimestamp + depositQuoteTimeBuffer,
             "invalid quote time"
         );
         // If the address of the origin token is a WETH contract and there is a msg.value with the transaction
@@ -822,7 +822,7 @@ abstract contract SpokePool is SpokePoolInterface, Testable, Lockable, MultiCall
         uint256 destinationChainId,
         uint64 relayerFeePct,
         uint32 depositId,
-        uint64 quoteTimestamp,
+        uint32 quoteTimestamp,
         address originToken,
         address recipient,
         address depositor
diff --git a/contracts/SpokePoolInterface.sol b/contracts/SpokePoolInterface.sol
index 82850c11d..5f49b0ca8 100644
--- a/contracts/SpokePoolInterface.sol
+++ b/contracts/SpokePoolInterface.sol
@@ -58,7 +58,7 @@ interface SpokePoolInterface {
         bool enable
     ) external;
 
-    function setDepositQuoteTimeBuffer(uint64 buffer) external;
+    function setDepositQuoteTimeBuffer(uint32 buffer) external;
 
     function relayRootBundle(bytes32 relayerRefundRoot, bytes32 slowRelayRoot) external;
 
@@ -70,7 +70,7 @@ interface SpokePoolInterface {
         uint256 amount,
         uint256 destinationChainId,
         uint64 relayerFeePct,
-        uint64 quoteTimestamp
+        uint32 quoteTimestamp
     ) external payable;
 
     function speedUpDeposit(