diff --git a/src/asymmetric_crypto/curve25519.rs b/src/asymmetric_crypto/curve25519.rs
index 0e03332..bc9d7f5 100644
--- a/src/asymmetric_crypto/curve25519.rs
+++ b/src/asymmetric_crypto/curve25519.rs
@@ -6,6 +6,11 @@
 //! time of this implementation.
 
 use crate::{asymmetric_crypto::DhKeyPair, CryptoCoreError, KeyTrait};
+use core::{
+    convert::TryFrom,
+    fmt::Display,
+    ops::{Add, Mul, Sub},
+};
 use curve25519_dalek::{
     constants,
     ristretto::{CompressedRistretto, RistrettoPoint},
@@ -13,11 +18,6 @@ use curve25519_dalek::{
 };
 use rand_core::{CryptoRng, RngCore};
 use serde::{Deserialize, Serialize};
-use std::{
-    convert::TryFrom,
-    fmt::Display,
-    ops::{Add, Mul, Sub},
-};
 use zeroize::{Zeroize, ZeroizeOnDrop};
 
 /// X25519 secret key length
@@ -120,7 +120,7 @@ impl TryFrom<&str> for X25519PrivateKey {
 
 /// Display the hex encoded value of the key
 impl Display for X25519PrivateKey {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "{}", hex::encode(self.0.as_bytes()))
     }
 }
@@ -308,7 +308,7 @@ impl TryFrom<&str> for X25519PublicKey {
 
 /// Display the hex encoded value of the key
 impl Display for X25519PublicKey {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "{}", hex::encode(self.0.compress().to_bytes()))
     }
 }
diff --git a/src/symmetric_crypto/aes_256_gcm_pure/mod.rs b/src/symmetric_crypto/aes_256_gcm_pure/mod.rs
index ca63938..92beb84 100644
--- a/src/symmetric_crypto/aes_256_gcm_pure/mod.rs
+++ b/src/symmetric_crypto/aes_256_gcm_pure/mod.rs
@@ -234,7 +234,7 @@ mod tests {
     fn test_encryption_decryption_detached() -> Result<(), CryptoCoreError> {
         let mut cs_rng = CsRng::new();
         let key = Key::<KEY_LENGTH>::new(&mut cs_rng);
-        let bytes = cs_rng.generate_random_bytes::<8192>();
+        let bytes = cs_rng.generate_random_bytes::<1024>();
         let iv = Nonce::<NONCE_LENGTH>::new(&mut cs_rng);
         // no additional data
         let mut data = bytes;
diff --git a/src/symmetric_crypto/key.rs b/src/symmetric_crypto/key.rs
index dbd3275..011477f 100644
--- a/src/symmetric_crypto/key.rs
+++ b/src/symmetric_crypto/key.rs
@@ -1,8 +1,8 @@
 //! Define a symmetric key object of variable size.
 
 use crate::{symmetric_crypto::SymKey, CryptoCoreError, KeyTrait};
+use core::{convert::TryFrom, fmt::Display, hash::Hash, ops::Deref};
 use rand_core::{CryptoRng, RngCore};
-use std::{convert::TryFrom, fmt::Display, hash::Hash, ops::Deref};
 use zeroize::{Zeroize, ZeroizeOnDrop};
 
 /// Symmetric key of a given size.
@@ -70,7 +70,7 @@ impl<'a, const KEY_LENGTH: usize> TryFrom<&'a [u8]> for Key<KEY_LENGTH> {
 }
 
 impl<const KEY_LENGTH: usize> Display for Key<KEY_LENGTH> {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "{}", hex::encode(self.as_bytes()))
     }
 }
@@ -108,7 +108,7 @@ impl<const KEY_LENGTH: usize> Deref for Key<KEY_LENGTH> {
 mod tests {
 
     use crate::{entropy::CsRng, symmetric_crypto::key::Key};
-    use std::ops::Deref;
+    use core::ops::Deref;
 
     const KEY_LENGTH: usize = 32;
 
diff --git a/src/symmetric_crypto/metadata.rs b/src/symmetric_crypto/metadata.rs
index 44117c1..9e1bf2d 100644
--- a/src/symmetric_crypto/metadata.rs
+++ b/src/symmetric_crypto/metadata.rs
@@ -1,6 +1,6 @@
 use crate::CryptoCoreError;
+use core::convert::TryInto;
 use serde::{Deserialize, Serialize};
-use std::convert::TryInto;
 
 /// Attempts to get the length of this slice as an `u32` in 4 endian bytes and
 /// returns an error if it overflows
diff --git a/src/symmetric_crypto/mod.rs b/src/symmetric_crypto/mod.rs
index 55ef7d4..9fc006c 100644
--- a/src/symmetric_crypto/mod.rs
+++ b/src/symmetric_crypto/mod.rs
@@ -12,9 +12,9 @@ pub use metadata::BytesScanner;
 pub use metadata::Metadata;
 
 use crate::{CryptoCoreError, KeyTrait};
+use core::hash::Hash;
 use nonce::NonceTrait;
 use rand_core::{CryptoRng, RngCore};
-use std::hash::Hash;
 use std::vec::Vec;
 
 /// Defines a symmetric encryption key.