diff --git a/apk_frauder/src/data_descriptor.rs b/apk_frauder/src/data_descriptor.rs
new file mode 100644
index 0000000..2daa834
--- /dev/null
+++ b/apk_frauder/src/data_descriptor.rs
@@ -0,0 +1,117 @@
+use crate::Signature;
+use androscalpel_serializer::{ReadSeek, Result, Serializable};
+use std::io::{SeekFrom, Write};
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum DataDescriptor {
+    Zip32(DataDescriptor32),
+    Zip64(DataDescriptor64),
+}
+
+/// DataDescriptor for 32bit zip format.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct DataDescriptor32 {
+    // signature: Option<Signature(0x08074b50)>
+    pub crc_32: u32,
+    pub compressed_size: u32,
+    pub uncompressed_size: u32,
+    /// For reproducibility. This should be true when writting a zip, but can be false when
+    /// reading one. If we want to stick to the original, we need to keep this information.
+    pub use_signature: bool,
+}
+
+/// DataDescriptor for 64bit zip format.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct DataDescriptor64 {
+    // signature: Option<Signature(0x08074b50)>
+    pub crc_32: u32,
+    pub compressed_size: u64,
+    pub uncompressed_size: u64,
+    /// For reproducibility. This should be true when writting a zip, but can be false when
+    /// reading one. If we want to stick to the original, we need to keep this information.
+    pub use_signature: bool,
+}
+
+impl DataDescriptor32 {
+    const SIGNATURE: Signature = Signature(0x02014b50);
+}
+
+impl Serializable for DataDescriptor32 {
+    fn serialize(&self, output: &mut dyn Write) -> Result<()> {
+        if self.use_signature {
+            Self::SIGNATURE.serialize(output)?;
+        }
+        self.crc_32.serialize(output)?;
+        self.compressed_size.serialize(output)?;
+        self.uncompressed_size.serialize(output)
+    }
+
+    fn deserialize(input: &mut dyn ReadSeek) -> Result<Self> {
+        let pos = input.stream_position().unwrap(); //TODO
+        let signature = Signature::deserialize(input)?;
+        let use_signature = if signature != Self::SIGNATURE {
+            input.seek(SeekFrom::Start(pos)).unwrap(); //TODO
+            false
+        } else {
+            true
+        };
+        let crc_32 = u32::deserialize(input)?;
+        let compressed_size = u32::deserialize(input)?;
+        let uncompressed_size = u32::deserialize(input)?;
+        Ok(Self {
+            crc_32,
+            compressed_size,
+            uncompressed_size,
+            use_signature,
+        })
+    }
+    fn size(&self) -> usize {
+        12 + if self.use_signature {
+            Self::SIGNATURE.size()
+        } else {
+            0
+        }
+    }
+}
+
+impl DataDescriptor64 {
+    const SIGNATURE: Signature = Signature(0x02014b50);
+}
+
+impl Serializable for DataDescriptor64 {
+    fn serialize(&self, output: &mut dyn Write) -> Result<()> {
+        if self.use_signature {
+            Self::SIGNATURE.serialize(output)?;
+        }
+        self.crc_32.serialize(output)?;
+        self.compressed_size.serialize(output)?;
+        self.uncompressed_size.serialize(output)
+    }
+
+    fn deserialize(input: &mut dyn ReadSeek) -> Result<Self> {
+        let pos = input.stream_position().unwrap(); //TODO
+        let signature = Signature::deserialize(input)?;
+        let use_signature = if signature != Self::SIGNATURE {
+            input.seek(SeekFrom::Start(pos)).unwrap(); //TODO
+            false
+        } else {
+            true
+        };
+        let crc_32 = u32::deserialize(input)?;
+        let compressed_size = u64::deserialize(input)?;
+        let uncompressed_size = u64::deserialize(input)?;
+        Ok(Self {
+            crc_32,
+            compressed_size,
+            uncompressed_size,
+            use_signature,
+        })
+    }
+    fn size(&self) -> usize {
+        20 + if self.use_signature {
+            Self::SIGNATURE.size()
+        } else {
+            0
+        }
+    }
+}