diff --git a/tlsn/Cargo.toml b/tlsn/Cargo.toml
index 4c0a4f35b..a957f2ab5 100644
--- a/tlsn/Cargo.toml
+++ b/tlsn/Cargo.toml
@@ -49,6 +49,7 @@ thiserror = "1"
 serde = "1"
 bincode = "1"
 hex = "0.4"
+bytes = "1.4"
 opaque-debug = "0.3"
 
 tracing = "0.1"
diff --git a/tlsn/tlsn-core/Cargo.toml b/tlsn/tlsn-core/Cargo.toml
index 64aacec49..8733a7a75 100644
--- a/tlsn/tlsn-core/Cargo.toml
+++ b/tlsn/tlsn-core/Cargo.toml
@@ -27,8 +27,9 @@ serde.workspace = true
 p256 = { workspace = true, features = ["serde"] }
 webpki-roots.workspace = true
 rs_merkle.workspace = true
-rstest = { workspace = true, optional = true}
-hex = { workspace = true, optional = true} 
+rstest = { workspace = true, optional = true }
+hex = { workspace = true, optional = true }
+bytes = { workspace = true, features = ["serde"] }
 tracing = { workspace = true, optional = true }
 
 [dev-dependencies]
diff --git a/tlsn/tlsn-core/src/transcript.rs b/tlsn/tlsn-core/src/transcript.rs
index 9b491e299..2f181724d 100644
--- a/tlsn/tlsn-core/src/transcript.rs
+++ b/tlsn/tlsn-core/src/transcript.rs
@@ -1,28 +1,36 @@
 //! This module contains code for transcripts of the TLSNotary session
 
-use crate::error::Error;
-use serde::{Deserialize, Serialize};
 use std::ops::Range;
 
+use bytes::Bytes;
+use serde::{Deserialize, Serialize};
+
+use crate::error::Error;
+
 /// A transcript contains a subset of bytes from a TLS session
 #[derive(Default, Serialize, Deserialize, Clone, Debug)]
 pub struct Transcript {
     id: String,
-    data: Vec<u8>,
+    data: Bytes,
 }
 
 impl Transcript {
     /// Creates a new transcript with the given ID and data
-    pub fn new(id: &str, data: Vec<u8>) -> Self {
+    pub fn new(id: &str, data: impl Into<Bytes>) -> Self {
         Self {
             id: id.to_string(),
-            data,
+            data: data.into(),
         }
     }
 
-    /// Extends the transcript with the given data
-    pub fn extend(&mut self, data: &[u8]) {
-        self.data.extend(data);
+    /// Returns the id used to identify this transcript
+    pub fn id(&self) -> &String {
+        &self.id
+    }
+
+    /// Returns the actual traffic data of this transcript
+    pub fn data(&self) -> &Bytes {
+        &self.data
     }
 
     /// Returns the value ID for each byte in the provided range
@@ -54,16 +62,6 @@ impl Transcript {
 
         Ok(dst)
     }
-
-    /// Returns the id used to identify this transcript
-    pub fn id(&self) -> &String {
-        &self.id
-    }
-
-    /// Returns the actual traffic data of this transcript
-    pub fn data(&self) -> &[u8] {
-        &self.data
-    }
 }
 
 /// Authenticated slice of [Transcript]. The [Direction] should be infered from some outer context.
@@ -140,7 +138,10 @@ mod tests {
             recv.get_bytes_in_ranges(&[range1, range2]).unwrap()
         );
 
-        assert_eq!(sent.data(), sent.get_bytes_in_ranges(&[range3]).unwrap());
+        assert_eq!(
+            sent.data().as_ref(),
+            sent.get_bytes_in_ranges(&[range3]).unwrap()
+        );
     }
 
     #[rstest]