diff --git a/no_std_test/src/main.rs b/no_std_test/src/main.rs
index c0e114a..d98276c 100644
--- a/no_std_test/src/main.rs
+++ b/no_std_test/src/main.rs
@@ -1,16 +1,4 @@
-// Bitcoin secp256k1 bindings
-// Written in 2019 by
-// Elichai Turkel
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see .
-//
+// SPDX-License-Identifier: CC0-1.0
//! # secp256k1 no-std test.
//! This binary is a short smallest rust code to produce a working binary *without libstd*.
diff --git a/secp256k1-sys/build.rs b/secp256k1-sys/build.rs
index 2d9f844..c151217 100644
--- a/secp256k1-sys/build.rs
+++ b/secp256k1-sys/build.rs
@@ -1,16 +1,4 @@
-// Bitcoin secp256k1 bindings
-// Written in 2015 by
-// Andrew Poelstra
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see .
-//
+// SPDX-License-Identifier: CC0-1.0
//! # Build script
diff --git a/secp256k1-sys/src/lib.rs b/secp256k1-sys/src/lib.rs
index 396df48..b8fe903 100644
--- a/secp256k1-sys/src/lib.rs
+++ b/secp256k1-sys/src/lib.rs
@@ -1,17 +1,5 @@
-// Bitcoin secp256k1 bindings
-// Written in 2014 by
-// Dawid Ciężarkiewicz
-// Andrew Poelstra
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see .
-//
+// SPDX-License-Identifier: CC0-1.0
+
//! # secp256k1-sys FFI bindings
//! Direct bindings to the underlying C library functions. These should
//! not be needed for most users.
diff --git a/secp256k1-sys/src/macros.rs b/secp256k1-sys/src/macros.rs
index 3f97245..ec225ab 100644
--- a/secp256k1-sys/src/macros.rs
+++ b/secp256k1-sys/src/macros.rs
@@ -1,17 +1,4 @@
-// Bitcoin secp256k1 bindings
-// Written in 2014 by
-// Dawid Ciężarkiewicz
-// Andrew Poelstra
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see .
-//
+// SPDX-License-Identifier: CC0-1.0
/// Implement methods and traits for types that contain an inner array.
#[macro_export]
diff --git a/secp256k1-sys/src/recovery.rs b/secp256k1-sys/src/recovery.rs
index 8899dc6..85db59e 100644
--- a/secp256k1-sys/src/recovery.rs
+++ b/secp256k1-sys/src/recovery.rs
@@ -1,17 +1,4 @@
-// Bitcoin secp256k1 bindings
-// Written in 2014 by
-// Dawid Ciężarkiewicz
-// Andrew Poelstra
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see .
-//
+// SPDX-License-Identifier: CC0-1.0
//! # FFI of the recovery module
diff --git a/secp256k1-sys/src/types.rs b/secp256k1-sys/src/types.rs
index e457ec4..28ef0fb 100644
--- a/secp256k1-sys/src/types.rs
+++ b/secp256k1-sys/src/types.rs
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: CC0-1.0
+
#![allow(non_camel_case_types)]
pub type c_int = i32;
diff --git a/src/constants.rs b/src/constants.rs
index 4b506f9..661ebaf 100644
--- a/src/constants.rs
+++ b/src/constants.rs
@@ -1,17 +1,4 @@
-// Bitcoin secp256k1 bindings
-// Written in 2014 by
-// Dawid Ciężarkiewicz
-// Andrew Poelstra
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see .
-//
+// SPDX-License-Identifier: CC0-1.0
//! Constants related to the API and the underlying curve.
//!
diff --git a/src/context.rs b/src/context.rs
index 5b41bc4..61ab985 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: CC0-1.0
+
use core::marker::PhantomData;
use core::mem::ManuallyDrop;
use core::ptr::NonNull;
diff --git a/src/ecdh.rs b/src/ecdh.rs
index f5d3a19..e01366e 100644
--- a/src/ecdh.rs
+++ b/src/ecdh.rs
@@ -1,16 +1,4 @@
-// Bitcoin secp256k1 bindings
-// Written in 2015 by
-// Andrew Poelstra
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see .
-//
+// SPDX-License-Identifier: CC0-1.0
//! Support for shared secret computations.
//!
diff --git a/src/ecdsa/mod.rs b/src/ecdsa/mod.rs
index 0e91193..fd01cbb 100644
--- a/src/ecdsa/mod.rs
+++ b/src/ecdsa/mod.rs
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: CC0-1.0
+
//! Structs and functionality related to the ECDSA signature algorithm.
//!
diff --git a/src/ecdsa/recovery.rs b/src/ecdsa/recovery.rs
index 6b63d8f..ab337d0 100644
--- a/src/ecdsa/recovery.rs
+++ b/src/ecdsa/recovery.rs
@@ -1,17 +1,4 @@
-// Bitcoin secp256k1 bindings
-// Written in 2014 by
-// Dawid Ciężarkiewicz
-// Andrew Poelstra
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see .
-//
+// SPDX-License-Identifier: CC0-1.0
//! Provides a signing function that allows recovering the public key from the
//! signature.
diff --git a/src/ecdsa/serialized_signature.rs b/src/ecdsa/serialized_signature.rs
index ab1f9e4..1b2a65a 100644
--- a/src/ecdsa/serialized_signature.rs
+++ b/src/ecdsa/serialized_signature.rs
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: CC0-1.0
+
//! Implements [`SerializedSignature`] and related types.
//!
//! DER-serialized signatures have the issue that they can have different lengths.
diff --git a/src/key.rs b/src/key.rs
index e32eaf1..c7559c7 100644
--- a/src/key.rs
+++ b/src/key.rs
@@ -1,17 +1,4 @@
-// Bitcoin secp256k1 bindings
-// Written in 2014 by
-// Dawid Ciężarkiewicz
-// Andrew Poelstra
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see .
-//
+// SPDX-License-Identifier: CC0-1.0
//! Public and secret keys.
//!
diff --git a/src/lib.rs b/src/lib.rs
index df67989..14d65f2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,17 +1,4 @@
-// Bitcoin secp256k1 bindings
-// Written in 2014 by
-// Dawid Ciężarkiewicz
-// Andrew Poelstra
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see .
-//
+// SPDX-License-Identifier: CC0-1.0
//! Rust bindings for Pieter Wuille's secp256k1 library, which is used for
//! fast and accurate manipulation of ECDSA signatures on the secp256k1
diff --git a/src/macros.rs b/src/macros.rs
index d5b78e9..4111b3f 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -1,17 +1,4 @@
-// Bitcoin secp256k1 bindings
-// Written in 2014 by
-// Dawid Ciężarkiewicz
-// Andrew Poelstra
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see .
-//
+// SPDX-License-Identifier: CC0-1.0
/// Implement methods and traits for types that contain an inner array.
#[macro_export]
diff --git a/src/scalar.rs b/src/scalar.rs
index 0736192..7ce5452 100644
--- a/src/scalar.rs
+++ b/src/scalar.rs
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: CC0-1.0
+
//! Provides [`Scalar`] and related types.
//!
//! In elliptic curve cryptography scalars are non-point values that can be used to multiply
diff --git a/src/schnorr.rs b/src/schnorr.rs
index 018beaa..e9488cc 100644
--- a/src/schnorr.rs
+++ b/src/schnorr.rs
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: CC0-1.0
+
//! Support for schnorr signatures.
//!
diff --git a/src/secret.rs b/src/secret.rs
index b744592..cec8a2f 100644
--- a/src/secret.rs
+++ b/src/secret.rs
@@ -1,16 +1,4 @@
-// Bitcoin secp256k1 bindings
-// Written in 2021 by
-// Maxim Orlovsky
-//
-// To the extent possible under law, the author(s) have dedicated all
-// copyright and related and neighboring rights to this software to
-// the public domain worldwide. This software is distributed without
-// any warranty.
-//
-// You should have received a copy of the CC0 Public Domain Dedication
-// along with this software.
-// If not, see .
-//
+// SPDX-License-Identifier: CC0-1.0
//! Helpers for displaying secret values
diff --git a/src/serde_util.rs b/src/serde_util.rs
index e2751dd..3b851b2 100644
--- a/src/serde_util.rs
+++ b/src/serde_util.rs
@@ -1,3 +1,5 @@
+// SPDX-License-Identifier: CC0-1.0
+
use core::fmt;
use core::marker::PhantomData;
use core::str::{self, FromStr};