From 85676d9cd197e2f992a1e1acf60b1ba556eaca67 Mon Sep 17 00:00:00 2001
From: cboh4 <bohdan@scrtlabs.com>
Date: Fri, 12 Sep 2025 14:01:55 +0300
Subject: [PATCH 1/2] remove ImplicitHash from the blockheader hash calculation

---
 state/state.go      | 10 +++++-----
 state/validation.go | 16 ++++++----------
 types/block.go      |  4 ++--
 3 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/state/state.go b/state/state.go
index f851bf84e01..e8fc523c544 100644
--- a/state/state.go
+++ b/state/state.go
@@ -280,10 +280,10 @@ func (state State) MakeBlock(
 		panic("Failed to validate generated random")
 	}
 
-	implicitHash, err := tmenclave.GetImplicitHash()
-	if err != nil {
-		panic("Failed to get implicit hash")
-	}
+	// implicitHash, err := tmenclave.GetImplicitHash()
+	// if err != nil {
+	// 	panic("Failed to get implicit hash")
+	// }
 	// ScrtLabs changes out <-
 
 	// Fill rest of header with state data.
@@ -292,7 +292,7 @@ func (state State) MakeBlock(
 		timestamp, state.LastBlockID,
 		state.Validators.Hash(), state.NextValidators.Hash(),
 		state.ConsensusParams.Hash(), state.AppHash, state.LastResultsHash,
-		proposerAddress, &encryptedRandom, implicitHash,
+		proposerAddress, &encryptedRandom, nil,
 	)
 
 	return block
diff --git a/state/validation.go b/state/validation.go
index 81dbc2f315a..9abc1846d22 100644
--- a/state/validation.go
+++ b/state/validation.go
@@ -2,7 +2,6 @@ package state
 
 import (
 	"bytes"
-	"crypto/sha256"
 	"encoding/hex"
 	"errors"
 	"fmt"
@@ -121,15 +120,12 @@ func validateBlock(state State, block *types.Block) error {
 		}
 	}
 
-	expectedImplicitHash, err := tmenclave.GetImplicitHash() // hash from last block's scheduling
-	if err != nil {
-		return fmt.Errorf("failed to get implicit hash: %w", err)
-	}
-	if !bytes.Equal(block.Header.ImplicitHash, expectedImplicitHash) {
-		emptySha256 := sha256.Sum256([]byte{})
-		if !(bytes.Equal(block.Header.ImplicitHash, []byte{}) && bytes.Equal(expectedImplicitHash, emptySha256[:])) {
-			return fmt.Errorf("implicit_hash mismatch: expected %X, got %X", hex.EncodeToString(expectedImplicitHash), hex.EncodeToString(block.Header.ImplicitHash))
-		}
+	// expectedImplicitHash, err := tmenclave.GetImplicitHash() // hash from last block's scheduling
+	// if err != nil {
+	// 	return fmt.Errorf("failed to get implicit hash: %w", err)
+	// }
+	if !bytes.Equal(block.Header.ImplicitHash, nil) {
+		return fmt.Errorf("implicit_hash mismatch: expected nil, got %s", block.Header.ImplicitHash.String())
 	}
 
 	// Validate block Time
diff --git a/types/block.go b/types/block.go
index aca900a54bf..e0f17119113 100644
--- a/types/block.go
+++ b/types/block.go
@@ -489,7 +489,7 @@ func (h *Header) Hash() cmtbytes.HexBytes {
 		cdcEncode(h.LastResultsHash),
 		cdcEncode(h.EvidenceHash),
 		cdcEncode(h.ProposerAddress),
-		cdcEncode(h.ImplicitHash),
+		// cdcEncode(h.ImplicitHash),
 	})
 }
 
@@ -529,7 +529,7 @@ func (h *Header) StringIndented(indent string) string {
 		indent, h.LastResultsHash,
 		indent, h.EvidenceHash,
 		indent, h.ProposerAddress,
-		indent, h.ImplicitHash,
+		// indent, h.ImplicitHash,
 		indent, h.Hash(),
 	)
 }

From da747a4af98de189973f90ae0cd5feff62f39af0 Mon Sep 17 00:00:00 2001
From: cboh4 <bohdan@scrtlabs.com>
Date: Fri, 12 Sep 2025 14:26:33 +0300
Subject: [PATCH 2/2] add check if it's a hash of empty slice

---
 state/validation.go | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/state/validation.go b/state/validation.go
index 9abc1846d22..b308fb43404 100644
--- a/state/validation.go
+++ b/state/validation.go
@@ -2,6 +2,7 @@ package state
 
 import (
 	"bytes"
+	"crypto/sha256"
 	"encoding/hex"
 	"errors"
 	"fmt"
@@ -124,8 +125,12 @@ func validateBlock(state State, block *types.Block) error {
 	// if err != nil {
 	// 	return fmt.Errorf("failed to get implicit hash: %w", err)
 	// }
-	if !bytes.Equal(block.Header.ImplicitHash, nil) {
-		return fmt.Errorf("implicit_hash mismatch: expected nil, got %s", block.Header.ImplicitHash.String())
+	if len(block.Header.ImplicitHash) > 0 {
+		emptySha256 := sha256.Sum256([]byte{})
+		if !bytes.Equal(block.Header.ImplicitHash, emptySha256[:]) {
+			return fmt.Errorf("implicit_hash mismatch: expected nil or empty hash, got %s",
+				block.Header.ImplicitHash.String())
+		}
 	}
 
 	// Validate block Time