diff --git a/bip32/src/lib.rs b/bip32/src/lib.rs
index ed97e21..16b8a12 100644
--- a/bip32/src/lib.rs
+++ b/bip32/src/lib.rs
@@ -22,17 +22,17 @@ pub struct Fingerprint(pub [u8; 4]);
 ///
 /// This contains the key derivation information about a public key.
 #[derive(Debug, Clone)]
-pub struct ExtendedPublicKey<'a> {
+pub struct ExtendedPublicKey {
     /// The version of the extended public key.
     pub version: [u8; 4],
     /// The depth of the extended public key.
     pub depth: u8,
     /// The fingerprint of the extended public key parent.
-    pub parent_fingerprint: &'a [u8],
+    pub parent_fingerprint: [u8; 4],
     /// The child number of the extended public key.
     pub child_number: u32,
     /// The chain code of the extended public key.
-    pub chain_code: &'a [u8],
+    pub chain_code: [u8; 32],
     /// The public key.
     pub public_key: PublicKey,
 }
@@ -46,12 +46,12 @@ pub struct ExtendedPublicKey<'a> {
 ///
 /// The buffer contained in the type should be always valid.
 #[derive(Debug, Clone)]
-pub struct DerivationPathLe<'a> {
-    buf: &'a [u8],
+pub struct DerivationPathLe<Input> {
+    buf: Input,
     len: usize,
 }
 
-impl<'a> DerivationPathLe<'a> {
+impl<Input> DerivationPathLe<Input> {
     /// Returns the number of elements in the derivation path.
     #[inline]
     pub fn len(&self) -> usize {
@@ -59,25 +59,41 @@ impl<'a> DerivationPathLe<'a> {
     }
 
     /// Returns an iterator over the elements of the derivation path.
-    pub fn iter(&self) -> DerivationPathLeIter {
-        DerivationPathLeIter { buf: self.buf }
+    pub fn iter(&self) -> DerivationPathLeIter<Input>
+    where
+        Input: Clone,
+    {
+        DerivationPathLeIter {
+            count: 0,
+            len: self.len,
+            buf: self.buf.clone(),
+        }
     }
 }
 
 /// Iterator over the derivation path elements.
-pub struct DerivationPathLeIter<'a> {
-    buf: &'a [u8],
+pub struct DerivationPathLeIter<Input> {
+    count: usize,
+    len: usize,
+    buf: Input,
 }
 
-impl<'a> Iterator for DerivationPathLeIter<'a> {
+impl<Input> Iterator for DerivationPathLeIter<Input>
+where
+    Input: Clone
+        + core::fmt::Debug
+        + nom::InputLength
+        + nom::InputIter<Item = u8>
+        + nom::Slice<core::ops::RangeFrom<usize>>,
+{
     type Item = u32;
 
     fn next(&mut self) -> Option<Self::Item> {
-        if self.buf.is_empty() {
+        if self.count >= self.len {
             return None;
         }
 
-        let (buf, item) = le_u32::<_, nom::error::Error<_>>(self.buf)
+        let (buf, item) = le_u32::<_, nom::error::Error<_>>(self.buf.clone())
             .expect("element should be valid at this point");
         self.buf = buf;
 
@@ -87,11 +103,11 @@ impl<'a> Iterator for DerivationPathLeIter<'a> {
 
 /// Information about an extended public key was derived.
 #[derive(Debug)]
-pub struct KeySource<'a> {
+pub struct KeySource<Input> {
     /// Fingerprint of the master key.
     pub fingerprint: Fingerprint,
     /// Derivation path of the key.
-    pub path: DerivationPathLe<'a>,
+    pub path: DerivationPathLe<Input>,
 }
 
 #[cfg(test)]
diff --git a/bip32/src/parser.rs b/bip32/src/parser.rs
index b4329d7..a864bbe 100644
--- a/bip32/src/parser.rs
+++ b/bip32/src/parser.rs
@@ -3,24 +3,40 @@
 
 //! Parser combinators for BIP-32 serialization formats.
 
-use nom::multi::fill;
+use core::ops::RangeFrom;
+
 use nom::{
     branch::alt,
     bytes::complete::{tag, take},
     combinator::{map, map_res, verify},
     error::{FromExternalError, ParseError},
-    multi::many0_count,
+    multi::{fill, many0_count},
     number::complete::{be_u32, le_u32, u8},
     sequence::tuple,
-    IResult,
+    Compare, IResult, InputIter, InputLength, InputTake, Slice,
 };
 use secp256k1::PublicKey;
 
 use crate::{DerivationPathLe, ExtendedPublicKey, Fingerprint, KeySource};
 
-fn bitcoin_mainnet_xpub<'a, Error: ParseError<&'a [u8]>>(
-    input: &'a [u8],
-) -> IResult<&[u8], &[u8], Error> {
+fn to_fixed_bytes<Input, const N: usize>(i: Input) -> [u8; N]
+where
+    Input: InputIter<Item = u8>,
+{
+    let mut slice = [0; N];
+    for (i, byte) in i.iter_indices() {
+        slice[i] = byte;
+    }
+    slice
+}
+
+fn bitcoin_mainnet_xpub<Input, Error>(i: Input) -> IResult<Input, Input, Error>
+where
+    Input: for<'a> Compare<&'a [u8]> + InputTake + Clone,
+    Error: ParseError<Input>,
+{
+    let tag = tag::<_, Input, Error>;
+
     let xpub = tag(&[0x04, 0x88, 0xb2, 0x1e]);
     let ypub = tag(&[0x04, 0x9d, 0x7c, 0xb2]);
     let zpub = tag(&[0x04, 0xb2, 0x47, 0x46]);
@@ -28,12 +44,16 @@ fn bitcoin_mainnet_xpub<'a, Error: ParseError<&'a [u8]>>(
     let multisig_zpub = tag(&[0x02, 0xaa, 0x7e, 0xd3]); // Zpub
 
     let mut parser = alt((xpub, ypub, zpub, multisig_ypub, multisig_zpub));
-    parser(input)
+    parser(i)
 }
 
-fn bitcoin_testnet_xpub<'a, Error: ParseError<&'a [u8]>>(
-    input: &'a [u8],
-) -> IResult<&[u8], &[u8], Error> {
+fn bitcoin_testnet_xpub<Input, Error>(i: Input) -> IResult<Input, Input, Error>
+where
+    Input: for<'a> Compare<&'a [u8]> + InputTake + Clone,
+    Error: ParseError<Input>,
+{
+    let tag = tag::<_, Input, Error>;
+
     let tpub = tag(&[0x04, 0x35, 0x87, 0xcf]);
     let upub = tag(&[0x04, 0x4a, 0x52, 0x62]);
     let vpub = tag(&[0x04, 0x5f, 0x1c, 0xf6]);
@@ -41,32 +61,43 @@ fn bitcoin_testnet_xpub<'a, Error: ParseError<&'a [u8]>>(
     let multisig_vpub = tag(&[0x02, 0x57, 0x54, 0x83]); // Vpub
 
     let mut parser = alt((tpub, upub, vpub, multisig_upub, multisig_vpub));
-    parser(input)
+    parser(i)
 }
 
-fn xpub_version<'a, Error: ParseError<&'a [u8]>>(i: &'a [u8]) -> IResult<&[u8], [u8; 4], Error> {
-    let bitcoin_xpub = alt((bitcoin_mainnet_xpub, bitcoin_testnet_xpub));
-
-    let mut version = map(bitcoin_xpub, |version| {
-        let mut tmp = [0; 4];
-        tmp.copy_from_slice(&version);
-        tmp
-    });
+fn xpub_version<Input, Error>(i: Input) -> IResult<Input, [u8; 4], Error>
+where
+    Input: for<'a> Compare<&'a [u8]> + InputTake + Clone + InputIter<Item = u8>,
+    Error: ParseError<Input>,
+{
+    let bitcoin_xpub = alt((
+        bitcoin_mainnet_xpub::<Input, Error>,
+        bitcoin_testnet_xpub::<Input, Error>,
+    ));
+    let mut version = map(bitcoin_xpub, to_fixed_bytes::<Input, 4>);
 
     version(i)
 }
 
 /// Parse an extended public key.
-pub fn extended_public_key<'a, Error>(i: &'a [u8]) -> IResult<&[u8], ExtendedPublicKey, Error>
+pub fn extended_public_key<Input, Error>(i: Input) -> IResult<Input, ExtendedPublicKey, Error>
 where
-    Error: ParseError<&'a [u8]>,
-    Error: FromExternalError<&'a [u8], secp256k1::Error>,
+    Input: for<'a> Compare<&'a [u8]>
+        + InputTake
+        + Clone
+        + InputIter<Item = u8>
+        + InputLength
+        + Slice<RangeFrom<usize>>,
+    Error: ParseError<Input>,
+    Error: FromExternalError<Input, secp256k1::Error>,
 {
-    let depth = u8;
-    let parent_fingerprint = take(4usize);
-    let child_number = be_u32;
-    let chain_code = take(32usize);
-    let public_key = map_res(take(33usize), PublicKey::from_slice);
+    let depth = u8::<Input, Error>;
+    let parent_fingerprint = map(take::<_, Input, Error>(4usize), to_fixed_bytes::<_, 4>);
+    let child_number = be_u32::<Input, Error>;
+    let chain_code = map(take::<_, Input, Error>(32usize), to_fixed_bytes::<_, 32>);
+    let public_key = map_res(
+        map(take::<_, Input, Error>(33usize), to_fixed_bytes::<_, 33>),
+        |pk| PublicKey::from_slice(&pk),
+    );
 
     let parser = tuple((
         xpub_version,
@@ -94,7 +125,7 @@ where
     let mut parser = verify(parser, |key| {
         // When the depth is 0 (master key) the parent fingerprint should be 0 and
         // child number should be 0 as well as it doesn't apply here.
-        if key.depth == 0 && (key.parent_fingerprint != &[0; 4] || key.child_number != 0) {
+        if key.depth == 0 && (&key.parent_fingerprint != &[0; 4] || key.child_number != 0) {
             false
         } else {
             true
@@ -108,26 +139,34 @@ where
 /// integers.
 ///
 /// `<derivation_path_le> := <le_u32>*`
-pub fn derivation_path_le<'a, Error: ParseError<&'a [u8]>>(
-    input: &'a [u8],
-) -> IResult<&[u8], DerivationPathLe, Error> {
-    let (next_input, len) = many0_count(le_u32)(input)?;
+pub fn derivation_path_le<Input, Error>(
+    input: Input,
+) -> IResult<Input, DerivationPathLe<Input>, Error>
+where
+    Input: Clone + Slice<RangeFrom<usize>> + InputIter<Item = u8> + InputLength,
+    Error: ParseError<Input>,
+{
+    let (next_input, len) = many0_count(le_u32)(input.clone())?;
     Ok((next_input, DerivationPathLe { buf: input, len }))
 }
 
 /// Parses a BIP-32 fingerprint.
-pub fn fingerprint<'a, Error: ParseError<&'a [u8]>>(
-    i: &'a [u8],
-) -> IResult<&'a [u8], Fingerprint, Error> {
+pub fn fingerprint<Input, Error>(i: Input) -> IResult<Input, Fingerprint, Error>
+where
+    Input: PartialEq + Clone + Slice<RangeFrom<usize>> + InputIter<Item = u8> + InputLength,
+    Error: ParseError<Input>,
+{
     let mut buf = [0; 4];
     let (i, _) = fill(u8, &mut buf)(i)?;
     Ok((i, Fingerprint(buf)))
 }
 
 /// Parses a [`KeySource`].
-pub fn key_source<'a, Error: ParseError<&'a [u8]>>(
-    i: &'a [u8],
-) -> IResult<&'a [u8], KeySource, Error> {
+pub fn key_source<Input, Error>(i: Input) -> IResult<Input, KeySource<Input>, Error>
+where
+    Input: PartialEq + Clone + Slice<RangeFrom<usize>> + InputIter<Item = u8> + InputLength,
+    Error: ParseError<Input>,
+{
     let fields = tuple((fingerprint, derivation_path_le));
     let mut parser = map(fields, |(fingerprint, path)| KeySource {
         fingerprint,
@@ -148,7 +187,8 @@ mod tests {
         for test_vector in vectors.valid {
             println!("Test vector: {}", test_vector.name);
             for chain in &test_vector.chains {
-                extended_public_key::<nom::error::Error<_>>(&chain.extended_public_key.0).unwrap();
+                let buf = chain.extended_public_key.as_slice();
+                extended_public_key::<_, nom::error::Error<_>>(buf).unwrap();
             }
         }
     }
@@ -162,7 +202,7 @@ mod tests {
             println!("Test vector: {}", test_vector.name);
             for (i, key) in test_vector.extended_keys.iter().enumerate() {
                 println!("Index: {}", i);
-                extended_public_key::<nom::error::Error<_>>(&key.0).unwrap_err();
+                extended_public_key::<_, nom::error::Error<_>>(key.as_slice()).unwrap_err();
             }
         }
     }
@@ -171,7 +211,7 @@ mod tests {
     fn parse_derivation_path_le() {
         const INPUT: &[u8] = &[0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80];
 
-        let (i, path) = derivation_path_le::<nom::error::Error<_>>(INPUT).unwrap();
+        let (i, path) = derivation_path_le::<_, nom::error::Error<_>>(INPUT).unwrap();
         assert!(i.is_empty());
         assert_eq!(path.buf, INPUT);
     }
@@ -180,7 +220,7 @@ mod tests {
     fn parse_key_source() {
         const INPUT: &[u8] = &[0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xEE, 0xFF, 0xFF];
 
-        let (i, source) = key_source::<nom::error::Error<_>>(INPUT).unwrap();
+        let (i, source) = key_source::<_, nom::error::Error<_>>(INPUT).unwrap();
         assert!(i.is_empty());
         assert_eq!(source.fingerprint, Fingerprint([0xAA, 0xBB, 0xCC, 0xDD]));
         assert_eq!(source.path.iter().next().unwrap(), 0xFFFF_EEEE);