From a4a049f5d7419216909de5b966e0dc98bf71bac7 Mon Sep 17 00:00:00 2001
From: Steve Fan <29133953+stevefan1999-personal@users.noreply.github.com>
Date: Wed, 28 May 2025 14:26:16 +0800
Subject: [PATCH 1/3] make zeroize optional

---
 Cargo.toml    |  5 +++--
 src/strobe.rs | 11 +++++++----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 5842c6b..7baeae0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,7 +20,7 @@ features = ["nightly"]
 [dependencies]
 keccak = { version = "0.1.0", default-features = false }
 byteorder = { version = "1.2.4", default-features = false }
-zeroize = { version = "1", default-features = false, features = ["zeroize_derive"] }
+zeroize = { version = "1", optional = true, default-features = false, features = ["zeroize_derive"] }
 rand_core = { version = "0.5", default-features = false }
 hex = {version = "0.3", default-features = false, optional = true}
 
@@ -30,7 +30,8 @@ curve25519-dalek = "2"
 rand_chacha = "0.2"
 
 [features]
-default = ["std"]
+default = ["std", "zeroize"]
 nightly = []
 debug-transcript = ["hex"]
 std = ["rand_core/std", "byteorder/std"]
+zeroize = ["dep:zeroize"]
\ No newline at end of file
diff --git a/src/strobe.rs b/src/strobe.rs
index ff0436f..7ca65c1 100644
--- a/src/strobe.rs
+++ b/src/strobe.rs
@@ -3,7 +3,9 @@
 use core::ops::{Deref, DerefMut};
 
 use keccak;
-use zeroize::Zeroize;
+
+#[cfg(feature = "zeroize")]
+use zeroize::{Zeroize, ZeroizeOnDrop};
 
 /// Strobe R value; security level 128 is hardcoded
 const STROBE_R: u8 = 166;
@@ -22,15 +24,16 @@ fn transmute_state(st: &mut AlignedKeccakState) -> &mut [u64; 25] {
 /// This is a wrapper around 200-byte buffer that's always 8-byte aligned
 /// to make pointers to it safely convertible to pointers to [u64; 25]
 /// (since u64 words must be 8-byte aligned)
-#[derive(Clone, Zeroize)]
-#[zeroize(drop)]
+#[derive(Clone)]
+#[cfg_attr(feature = "zeroize", derive(Zeroize, ZeroizeOnDrop))]
 #[repr(align(8))]
 struct AlignedKeccakState([u8; 200]);
 
 /// A Strobe context for the 128-bit security level.
 ///
 /// Only `meta-AD`, `AD`, `KEY`, and `PRF` operations are supported.
-#[derive(Clone, Zeroize)]
+#[derive(Clone)]
+#[cfg_attr(feature = "zeroize", derive(Zeroize, ZeroizeOnDrop))]
 pub struct Strobe128 {
     state: AlignedKeccakState,
     pos: u8,

From 9e4dd8c9393d9e4b0448f2ad13eeb94ac4109f90 Mon Sep 17 00:00:00 2001
From: Steve Fan <29133953+stevefan1999-personal@users.noreply.github.com>
Date: Wed, 28 May 2025 14:29:43 +0800
Subject: [PATCH 2/3] fixup! make zeroize optional

---
 src/transcript.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/transcript.rs b/src/transcript.rs
index 9b72f48..d605066 100644
--- a/src/transcript.rs
+++ b/src/transcript.rs
@@ -1,5 +1,6 @@
 use rand_core;
-use zeroize::Zeroize;
+#[cfg(feature = "zeroize")]
+use zeroize::{Zeroize, ZeroizeOnDrop};
 
 use crate::strobe::Strobe128;
 
@@ -50,7 +51,8 @@ fn encode_usize_as_u32(x: usize) -> [u8; 4] {
 /// implement a proof system, see the documentation at
 /// [merlin.cool](https://merlin.cool), particularly the [Using
 /// Merlin](https://merlin.cool/use/index.html) section.
-#[derive(Clone, Zeroize)]
+#[derive(Clone)]
+#[cfg_attr(feature = "zeroize", derive(Zeroize, ZeroizeOnDrop))]
 pub struct Transcript {
     strobe: Strobe128,
 }

From e9b9078ed87e4f61a919f26f2f59c9c7087e9f1a Mon Sep 17 00:00:00 2001
From: Steve Fan <29133953+stevefan1999-personal@users.noreply.github.com>
Date: Wed, 28 May 2025 14:33:28 +0800
Subject: [PATCH 3/3] Update Cargo.toml

---
 Cargo.toml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 7baeae0..d695987 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -30,8 +30,8 @@ curve25519-dalek = "2"
 rand_chacha = "0.2"
 
 [features]
-default = ["std", "zeroize"]
+default = ["std"]
 nightly = []
 debug-transcript = ["hex"]
 std = ["rand_core/std", "byteorder/std"]
-zeroize = ["dep:zeroize"]
\ No newline at end of file
+zeroize = ["dep:zeroize"]