diff --git a/abciapp/block_challenge.go b/abciapp/block_challenge.go
index 9ad5656..0de34e3 100644
--- a/abciapp/block_challenge.go
+++ b/abciapp/block_challenge.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"embed"
+	"errors"
 	"math/big"
 	"time"
 
@@ -199,41 +200,48 @@ func (c *blockChallengeCoordinator) computeBlockChallengeProof(tx transaction.Re
 	return buf.Bytes(), nil
 }
 
-func (c *blockChallengeCoordinator) verifyBlockChallengeProof(height int64, validatorAddress []byte, proofBytes []byte) (bool, error) {
+var bn254IDScalarField = bn254.ID.ScalarField()
+
+var errInvalidBlockChallengeProof = errors.New("invalid block challenge proof")
+
+func (c *blockChallengeCoordinator) verifyBlockChallengeProof(height int64, validatorAddress []byte, proofBytes []byte) error {
 	// timestamp shouldn't matter for this
 	// it is however important that we read the tree exactly as it was on the height prior to the one where the proof was supposedly generated
 	// this is because operations can change over time (nullification) and also the returned data for the highest operation indexes will be different
 	tx, err := c.txFactory.ReadHeight(time.Time{}, height-1)
 	if err != nil {
-		return false, stacktrace.Propagate(err)
+		return stacktrace.Propagate(err)
 	}
 
 	sharedPart, err := c.fetchOrBuildBlockChallengeCircuitAssignmentShared(tx, height)
 	if err != nil {
-		return false, stacktrace.Propagate(err)
+		return stacktrace.Propagate(err)
 	}
 
 	assignment := buildBlockChallengeCircuitAssignmentFull(sharedPart, validatorAddress)
 
-	witness, err := frontend.NewWitness(assignment, bn254.ID.ScalarField())
+	witness, err := frontend.NewWitness(assignment, bn254IDScalarField)
 	if err != nil {
-		return false, stacktrace.Propagate(err)
+		return stacktrace.Propagate(err)
 	}
 
 	publicWitness, err := witness.Public()
 	if err != nil {
-		return false, stacktrace.Propagate(err)
+		return stacktrace.Propagate(err)
 	}
 
 	proof := groth16.NewProof(bn254.ID)
 
 	_, err = proof.ReadFrom(bytes.NewBuffer(proofBytes))
 	if err != nil {
-		return false, stacktrace.Propagate(err)
+		return stacktrace.Propagate(errors.Join(errInvalidBlockChallengeProof, err))
 	}
 
 	err = groth16.Verify(proof, blockChallengeVerifyingKey, publicWitness)
-	return err == nil, nil
+	if err != nil {
+		return stacktrace.Propagate(errors.Join(errInvalidBlockChallengeProof, err))
+	}
+	return nil
 }
 
 func (c *blockChallengeCoordinator) buildPrivateChallengeWitnessForHeight(tx transaction.Read, height int64) (witness.Witness, error) {
@@ -244,7 +252,7 @@ func (c *blockChallengeCoordinator) buildPrivateChallengeWitnessForHeight(tx tra
 
 	assignment := buildBlockChallengeCircuitAssignmentFull(sharedPart, c.validatorAddress)
 
-	witness, err := frontend.NewWitness(assignment, bn254.ID.ScalarField())
+	witness, err := frontend.NewWitness(assignment, bn254IDScalarField)
 	return witness, stacktrace.Propagate(err)
 }
 
@@ -258,7 +266,7 @@ func (c *blockChallengeCoordinator) blockChallengeOperationDataForHeight(tx tran
 		return nil, nil, stacktrace.Propagate(err)
 	}
 	lastCommitHash := blockHeader.LastCommitHash
-	lastCommitHashBigInt := big.NewInt(0).SetBytes(lastCommitHash)
+	lastCommitHashBigInt := new(big.Int).SetBytes(lastCommitHash)
 
 	highestOp, err := tx.CountOperations()
 	if err != nil {
@@ -269,7 +277,7 @@ func (c *blockChallengeCoordinator) blockChallengeOperationDataForHeight(tx tran
 	operationData := make([]byte, initialOpDataLen)
 	operationDataCursor := 0
 	if highestOp > 0 {
-		startOpIdxBigInt := big.NewInt(0).Mod(lastCommitHashBigInt, big.NewInt(0).SetUint64(highestOp-1))
+		startOpIdxBigInt := new(big.Int).Mod(lastCommitHashBigInt, new(big.Int).SetUint64(highestOp-1))
 		startOpIdx := startOpIdxBigInt.Uint64()
 		// the starting operation sequence is startOpIdx+1
 		// because operations sequences start at 1 but the result of the modulus is (0, n(
diff --git a/abciapp/execution.go b/abciapp/execution.go
index 2e90d88..3d702e0 100644
--- a/abciapp/execution.go
+++ b/abciapp/execution.go
@@ -251,13 +251,17 @@ func (d *DIDPLCApplication) VerifyVoteExtension(_ context.Context, req *abcitype
 		}, nil
 	}
 
-	proofOK, err := d.blockChallengeCoordinator.verifyBlockChallengeProof(req.Height, req.ValidatorAddress, req.VoteExtension)
-	if err != nil {
+	err := d.blockChallengeCoordinator.verifyBlockChallengeProof(req.Height, req.ValidatorAddress, req.VoteExtension)
+	if errors.Is(err, errInvalidBlockChallengeProof) {
+		return &abcitypes.ResponseVerifyVoteExtension{
+			Status: abcitypes.ResponseVerifyVoteExtension_REJECT,
+		}, nil
+	} else if err != nil {
 		return nil, stacktrace.Propagate(err)
 	}
 
 	return &abcitypes.ResponseVerifyVoteExtension{
-		Status: lo.Ternary(proofOK, abcitypes.ResponseVerifyVoteExtension_ACCEPT, abcitypes.ResponseVerifyVoteExtension_REJECT),
+		Status: abcitypes.ResponseVerifyVoteExtension_ACCEPT,
 	}, nil
 }
 
diff --git a/abciapp/tx_challenge.go b/abciapp/tx_challenge.go
index 1822df3..c6d0a10 100644
--- a/abciapp/tx_challenge.go
+++ b/abciapp/tx_challenge.go
@@ -17,7 +17,7 @@ import (
 var TransactionActionCommitToChallenge = registerTransactionAction[CommitToChallengeArguments]("CommitToChallenge", processCommitToChallengeTx)
 
 const CommitToChallengeMaxAgeInBlocks = 3
-const CommitToChallengeMinRange = 1000
+const CommitToChallengeMinRange = 1950
 const CommitToChallengeMaxRange = 5000
 const CommitToChallengeTargetInterval = 2000
 
@@ -159,15 +159,14 @@ func processCommitToChallengeTx(ctx context.Context, deps TransactionProcessorDe
 		}, nil
 	}
 
-	blockProofValid, err := deps.blockChallengeCoordinator.verifyBlockChallengeProof(int64(proofHeight), validatorPubKey.Address(), existenceProof.Value)
-	if err != nil {
-		return nil, stacktrace.Propagate(err)
-	}
-	if !blockProofValid {
+	err = deps.blockChallengeCoordinator.verifyBlockChallengeProof(int64(proofHeight), validatorPubKey.Address(), existenceProof.Value)
+	if errors.Is(err, errInvalidBlockChallengeProof) {
 		return &processResult{
 			Code: 4211,
 			Log:  "invalid proof",
 		}, nil
+	} else if err != nil {
+		return nil, stacktrace.Propagate(err)
 	}
 
 	if !ics23.VerifyMembership(ics23.IavlSpec, tx.Arguments.Root, proof, existenceProof.Key, existenceProof.Value) {
@@ -298,15 +297,14 @@ func processCompleteChallengeTx(ctx context.Context, deps TransactionProcessorDe
 		}, nil
 	}
 
-	blockProofValid, err := deps.blockChallengeCoordinator.verifyBlockChallengeProof(int64(proofHeight), pubKey.Address(), existenceProof.Value)
-	if err != nil {
-		return nil, stacktrace.Propagate(err)
-	}
-	if !blockProofValid {
+	err = deps.blockChallengeCoordinator.verifyBlockChallengeProof(int64(proofHeight), pubKey.Address(), existenceProof.Value)
+	if errors.Is(err, errInvalidBlockChallengeProof) {
 		return &processResult{
 			Code: 4307,
 			Log:  "invalid proof",
 		}, nil
+	} else if err != nil {
+		return nil, stacktrace.Propagate(err)
 	}
 
 	if !ics23.VerifyMembership(ics23.IavlSpec, committedTreeRoot, proof, existenceProof.Key, existenceProof.Value) {