diff --git a/crates/iceberg/public-api.txt b/crates/iceberg/public-api.txt
index eb2d4f932b..0a980589f2 100644
--- a/crates/iceberg/public-api.txt
+++ b/crates/iceberg/public-api.txt
@@ -2078,7 +2078,7 @@ pub fn iceberg::spec::ManifestWriterBuilder::build_v2_data(self) -> iceberg::spe
 pub fn iceberg::spec::ManifestWriterBuilder::build_v2_deletes(self) -> iceberg::spec::ManifestWriter
 pub fn iceberg::spec::ManifestWriterBuilder::build_v3_data(self) -> iceberg::spec::ManifestWriter
 pub fn iceberg::spec::ManifestWriterBuilder::build_v3_deletes(self) -> iceberg::spec::ManifestWriter
-pub fn iceberg::spec::ManifestWriterBuilder::new(output: iceberg::io::OutputFile, snapshot_id: core::option::Option<i64>, key_metadata: core::option::Option<alloc::vec::Vec<u8>>, schema: iceberg::spec::SchemaRef, partition_spec: iceberg::spec::PartitionSpec) -> Self
+pub fn iceberg::spec::ManifestWriterBuilder::new(output: iceberg::io::OutputFile, snapshot_id: core::option::Option<i64>, schema: iceberg::spec::SchemaRef, partition_spec: iceberg::spec::PartitionSpec) -> Self
 pub fn iceberg::spec::ManifestWriterBuilder::new_from_encrypted(encrypted_output: iceberg::encryption::EncryptedOutputFile, snapshot_id: core::option::Option<i64>, key_metadata: core::option::Option<alloc::vec::Vec<u8>>, schema: iceberg::spec::SchemaRef, partition_spec: iceberg::spec::PartitionSpec) -> Self
 pub struct iceberg::spec::Map
 impl iceberg::spec::Map
diff --git a/crates/iceberg/src/io/object_cache.rs b/crates/iceberg/src/io/object_cache.rs
index d724c6ecda..9d7815569b 100644
--- a/crates/iceberg/src/io/object_cache.rs
+++ b/crates/iceberg/src/io/object_cache.rs
@@ -293,7 +293,6 @@ mod tests {
             let mut writer = ManifestWriterBuilder::new(
                 self.next_manifest_file(),
                 Some(current_snapshot.snapshot_id()),
-                None,
                 current_schema.clone(),
                 current_partition_spec.as_ref().clone(),
             )
diff --git a/crates/iceberg/src/scan/mod.rs b/crates/iceberg/src/scan/mod.rs
index 368e8143e2..0c089be5a5 100644
--- a/crates/iceberg/src/scan/mod.rs
+++ b/crates/iceberg/src/scan/mod.rs
@@ -825,7 +825,6 @@ pub mod tests {
             let mut writer = ManifestWriterBuilder::new(
                 self.next_manifest_file(),
                 Some(current_snapshot.snapshot_id()),
-                None,
                 current_schema.clone(),
                 current_partition_spec.as_ref().clone(),
             )
@@ -1054,7 +1053,6 @@ pub mod tests {
             let mut writer = ManifestWriterBuilder::new(
                 self.next_manifest_file(),
                 Some(current_snapshot.snapshot_id()),
-                None,
                 current_schema.clone(),
                 current_partition_spec.as_ref().clone(),
             )
@@ -1165,7 +1163,6 @@ pub mod tests {
             let mut writer = ManifestWriterBuilder::new(
                 self.next_manifest_file(),
                 Some(current_snapshot.snapshot_id()),
-                None,
                 current_schema.clone(),
                 current_partition_spec.as_ref().clone(),
             )
@@ -1200,7 +1197,6 @@ pub mod tests {
             let mut writer = ManifestWriterBuilder::new(
                 self.next_manifest_file(),
                 Some(current_snapshot.snapshot_id()),
-                None,
                 current_schema.clone(),
                 current_partition_spec.as_ref().clone(),
             )
diff --git a/crates/iceberg/src/spec/manifest/mod.rs b/crates/iceberg/src/spec/manifest/mod.rs
index fca753ecb2..4ba2645f51 100644
--- a/crates/iceberg/src/spec/manifest/mod.rs
+++ b/crates/iceberg/src/spec/manifest/mod.rs
@@ -270,7 +270,6 @@ mod tests {
         let mut writer = ManifestWriterBuilder::new(
             output_file,
             Some(1),
-            None,
             metadata.schema.clone(),
             metadata.partition_spec.clone(),
         )
@@ -572,7 +571,6 @@ mod tests {
         let mut writer = ManifestWriterBuilder::new(
             output_file,
             Some(2),
-            None,
             metadata.schema.clone(),
             metadata.partition_spec.clone(),
         )
@@ -669,7 +667,6 @@ mod tests {
         let mut writer = ManifestWriterBuilder::new(
             output_file,
             Some(3),
-            None,
             metadata.schema.clone(),
             metadata.partition_spec.clone(),
         )
@@ -778,7 +775,6 @@ mod tests {
         let mut writer = ManifestWriterBuilder::new(
             output_file,
             Some(2),
-            None,
             metadata.schema.clone(),
             metadata.partition_spec.clone(),
         )
@@ -886,7 +882,6 @@ mod tests {
         let mut writer = ManifestWriterBuilder::new(
             output_file,
             Some(2),
-            None,
             metadata.schema.clone(),
             metadata.partition_spec.clone(),
         )
@@ -1165,7 +1160,6 @@ mod tests {
         let mut writer = ManifestWriterBuilder::new(
             output_file,
             Some(1),
-            None,
             metadata.schema.clone(),
             metadata.partition_spec.clone(),
         )
diff --git a/crates/iceberg/src/spec/manifest/writer.rs b/crates/iceberg/src/spec/manifest/writer.rs
index 88da1a396c..9fa2cc1c7a 100644
--- a/crates/iceberg/src/spec/manifest/writer.rs
+++ b/crates/iceberg/src/spec/manifest/writer.rs
@@ -56,11 +56,10 @@ pub struct ManifestWriterBuilder {
 }
 
 impl ManifestWriterBuilder {
-    /// Create a new builder.
+    /// Create a new builder for unencrypted manifests.
     pub fn new(
         output: OutputFile,
         snapshot_id: Option<i64>,
-        key_metadata: Option<Vec<u8>>,
         schema: SchemaRef,
         partition_spec: PartitionSpec,
     ) -> Self {
@@ -69,7 +68,7 @@ impl ManifestWriterBuilder {
             writer_future: Box::pin(async move { output.writer().await }),
             location,
             snapshot_id,
-            key_metadata,
+            key_metadata: None,
             schema,
             partition_spec,
         }
@@ -732,7 +731,6 @@ mod tests {
         let mut writer = ManifestWriterBuilder::new(
             output_file,
             Some(3),
-            None,
             metadata.schema.clone(),
             metadata.partition_spec.clone(),
         )
@@ -820,7 +818,6 @@ mod tests {
         let mut writer = ManifestWriterBuilder::new(
             output_file,
             Some(1),
-            None,
             schema.clone(),
             partition_spec.clone(),
         )
diff --git a/crates/iceberg/src/transaction/append.rs b/crates/iceberg/src/transaction/append.rs
index 36fde117ab..01e7556e14 100644
--- a/crates/iceberg/src/transaction/append.rs
+++ b/crates/iceberg/src/transaction/append.rs
@@ -34,7 +34,6 @@ pub struct FastAppendAction {
     check_duplicate: bool,
     // below are properties used to create SnapshotProducer when commit
     commit_uuid: Option<Uuid>,
-    key_metadata: Option<Vec<u8>>,
     snapshot_properties: HashMap<String, String>,
     added_data_files: Vec<DataFile>,
 }
@@ -44,7 +43,6 @@ impl FastAppendAction {
         Self {
             check_duplicate: true,
             commit_uuid: None,
-            key_metadata: None,
             snapshot_properties: HashMap::default(),
             added_data_files: vec![],
         }
@@ -68,12 +66,6 @@ impl FastAppendAction {
         self
     }
 
-    /// Set key metadata for manifest files.
-    pub fn set_key_metadata(mut self, key_metadata: Vec<u8>) -> Self {
-        self.key_metadata = Some(key_metadata);
-        self
-    }
-
     /// Set snapshot summary properties.
     pub fn set_snapshot_properties(mut self, snapshot_properties: HashMap<String, String>) -> Self {
         self.snapshot_properties = snapshot_properties;
@@ -87,7 +79,6 @@ impl TransactionAction for FastAppendAction {
         let snapshot_producer = SnapshotProducer::new(
             table,
             self.commit_uuid.unwrap_or_else(Uuid::now_v7),
-            self.key_metadata.clone(),
             self.snapshot_properties.clone(),
             self.added_data_files.clone(),
         );
@@ -233,7 +224,6 @@ mod tests {
         let mut data_writer = ManifestWriterBuilder::new(
             next_manifest_file(&table_location_str),
             Some(current_snapshot.snapshot_id()),
-            None,
             schema.clone(),
             partition_spec.as_ref().clone(),
         )
@@ -263,7 +253,6 @@ mod tests {
         let mut delete_writer = ManifestWriterBuilder::new(
             next_manifest_file(&table_location_str),
             Some(current_snapshot.snapshot_id()),
-            None,
             schema.clone(),
             partition_spec.as_ref().clone(),
         )
diff --git a/crates/iceberg/src/transaction/snapshot.rs b/crates/iceberg/src/transaction/snapshot.rs
index 8e47226072..1389e3e60e 100644
--- a/crates/iceberg/src/transaction/snapshot.rs
+++ b/crates/iceberg/src/transaction/snapshot.rs
@@ -113,7 +113,6 @@ pub(crate) struct SnapshotProducer<'a> {
     pub(crate) table: &'a Table,
     snapshot_id: i64,
     commit_uuid: Uuid,
-    key_metadata: Option<Vec<u8>>,
     snapshot_properties: HashMap<String, String>,
     added_data_files: Vec<DataFile>,
     // A counter used to generate unique manifest file names.
@@ -126,7 +125,6 @@ impl<'a> SnapshotProducer<'a> {
     pub(crate) fn new(
         table: &'a Table,
         commit_uuid: Uuid,
-        key_metadata: Option<Vec<u8>>,
         snapshot_properties: HashMap<String, String>,
         added_data_files: Vec<DataFile>,
     ) -> Self {
@@ -134,7 +132,6 @@ impl<'a> SnapshotProducer<'a> {
             table,
             snapshot_id: Self::generate_unique_snapshot_id(table),
             commit_uuid,
-            key_metadata,
             snapshot_properties,
             added_data_files,
             manifest_counter: (0..),
@@ -255,7 +252,6 @@ impl<'a> SnapshotProducer<'a> {
         let builder = ManifestWriterBuilder::new(
             output_file,
             Some(self.snapshot_id),
-            self.key_metadata.clone(),
             self.table.metadata().current_schema().clone(),
             self.table
                 .metadata()