diff --git a/weed/pb/volume_server.proto b/weed/pb/volume_server.proto
index bb0572589..7c2951676 100644
--- a/weed/pb/volume_server.proto
+++ b/weed/pb/volume_server.proto
@@ -478,6 +478,8 @@ message VolumeEcShardReadRequest {
     int64 offset = 3;
     int64 size = 4;
     uint64 file_key = 5;
+    reserved 6;
+    int64 encode_ts_ns = 7; // caller's expected encode time; the server rejects a shard from a different encode run
 }
 message VolumeEcShardReadResponse {
     bytes data = 1;
@@ -580,6 +582,7 @@ message VolumeInfo {
 message EcShardConfig {
     uint32 data_shards = 1;   // Number of data shards (e.g., 10)
     uint32 parity_shards = 2; // Number of parity shards (e.g., 4)
+    int64 encode_ts_ns = 3;   // encode time (unix nanos); a read served from a shard of a different encode run is rejected
 }
 
 // EcBitrotProtection is the entire content of a bitrot checksum sidecar
diff --git a/weed/pb/volume_server_pb/volume_server.pb.go b/weed/pb/volume_server_pb/volume_server.pb.go
index 3d2ef4266..d6b25290a 100644
--- a/weed/pb/volume_server_pb/volume_server.pb.go
+++ b/weed/pb/volume_server_pb/volume_server.pb.go
@@ -3895,6 +3895,7 @@ type VolumeEcShardReadRequest struct {
 	Offset        int64                  `protobuf:"varint,3,opt,name=offset,proto3" json:"offset,omitempty"`
 	Size          int64                  `protobuf:"varint,4,opt,name=size,proto3" json:"size,omitempty"`
 	FileKey       uint64                 `protobuf:"varint,5,opt,name=file_key,json=fileKey,proto3" json:"file_key,omitempty"`
+	EncodeTsNs    int64                  `protobuf:"varint,7,opt,name=encode_ts_ns,json=encodeTsNs,proto3" json:"encode_ts_ns,omitempty"` // caller's expected encode time; the server rejects a shard from a different encode run
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -3964,6 +3965,13 @@ func (x *VolumeEcShardReadRequest) GetFileKey() uint64 {
 	return 0
 }
 
+func (x *VolumeEcShardReadRequest) GetEncodeTsNs() int64 {
+	if x != nil {
+		return x.EncodeTsNs
+	}
+	return 0
+}
+
 type VolumeEcShardReadResponse struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	Data          []byte                 `protobuf:"bytes,1,opt,name=data,proto3" json:"data,omitempty"`
@@ -4946,6 +4954,7 @@ type EcShardConfig struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	DataShards    uint32                 `protobuf:"varint,1,opt,name=data_shards,json=dataShards,proto3" json:"data_shards,omitempty"`       // Number of data shards (e.g., 10)
 	ParityShards  uint32                 `protobuf:"varint,2,opt,name=parity_shards,json=parityShards,proto3" json:"parity_shards,omitempty"` // Number of parity shards (e.g., 4)
+	EncodeTsNs    int64                  `protobuf:"varint,3,opt,name=encode_ts_ns,json=encodeTsNs,proto3" json:"encode_ts_ns,omitempty"`     // encode time (unix nanos); a read served from a shard of a different encode run is rejected
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -4994,6 +5003,13 @@ func (x *EcShardConfig) GetParityShards() uint32 {
 	return 0
 }
 
+func (x *EcShardConfig) GetEncodeTsNs() int64 {
+	if x != nil {
+		return x.EncodeTsNs
+	}
+	return 0
+}
+
 // EcBitrotProtection is the entire content of a bitrot checksum sidecar
 // (<base>.ecsum for the legacy generation, <base>.ecsum.v<N> for vacuum
 // generation N). On disk it is wrapped in a fixed header carrying a CRC32C
@@ -7247,13 +7263,15 @@ const file_volume_server_proto_rawDesc = "" +
 	"\x1cVolumeEcShardsUnmountRequest\x12\x1b\n" +
 	"\tvolume_id\x18\x01 \x01(\rR\bvolumeId\x12\x1b\n" +
 	"\tshard_ids\x18\x03 \x03(\rR\bshardIds\"\x1f\n" +
-	"\x1dVolumeEcShardsUnmountResponse\"\x99\x01\n" +
+	"\x1dVolumeEcShardsUnmountResponse\"\xc1\x01\n" +
 	"\x18VolumeEcShardReadRequest\x12\x1b\n" +
 	"\tvolume_id\x18\x01 \x01(\rR\bvolumeId\x12\x19\n" +
 	"\bshard_id\x18\x02 \x01(\rR\ashardId\x12\x16\n" +
 	"\x06offset\x18\x03 \x01(\x03R\x06offset\x12\x12\n" +
 	"\x04size\x18\x04 \x01(\x03R\x04size\x12\x19\n" +
-	"\bfile_key\x18\x05 \x01(\x04R\afileKey\"N\n" +
+	"\bfile_key\x18\x05 \x01(\x04R\afileKey\x12 \n" +
+	"\fencode_ts_ns\x18\a \x01(\x03R\n" +
+	"encodeTsNsJ\x04\b\x06\x10\a\"N\n" +
 	"\x19VolumeEcShardReadResponse\x12\x12\n" +
 	"\x04data\x18\x01 \x01(\fR\x04data\x12\x1d\n" +
 	"\n" +
@@ -7346,11 +7364,13 @@ const file_volume_server_proto_rawDesc = "" +
 	"\rdat_file_size\x18\x05 \x01(\x03R\vdatFileSize\x12\"\n" +
 	"\rexpire_at_sec\x18\x06 \x01(\x04R\vexpireAtSec\x12\x1b\n" +
 	"\tread_only\x18\a \x01(\bR\breadOnly\x12G\n" +
-	"\x0fec_shard_config\x18\b \x01(\v2\x1f.volume_server_pb.EcShardConfigR\recShardConfig\"U\n" +
+	"\x0fec_shard_config\x18\b \x01(\v2\x1f.volume_server_pb.EcShardConfigR\recShardConfig\"w\n" +
 	"\rEcShardConfig\x12\x1f\n" +
 	"\vdata_shards\x18\x01 \x01(\rR\n" +
 	"dataShards\x12#\n" +
-	"\rparity_shards\x18\x02 \x01(\rR\fparityShards\"\xbc\x02\n" +
+	"\rparity_shards\x18\x02 \x01(\rR\fparityShards\x12 \n" +
+	"\fencode_ts_ns\x18\x03 \x01(\x03R\n" +
+	"encodeTsNs\"\xbc\x02\n" +
 	"\x12EcBitrotProtection\x12A\n" +
 	"\talgorithm\x18\x01 \x01(\x0e2#.volume_server_pb.ChecksumAlgorithmR\talgorithm\x12\x1d\n" +
 	"\n" +