diff --git a/Cargo.lock b/Cargo.lock
index eefda513ca..eb164bef1f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -102,7 +102,7 @@ dependencies = [
 [[package]]
 name = "amcl"
 version = "0.2.0"
-source = "git+https://github.com/sigp/milagro_bls?tag=v1.0.1#2ccdd4b517c1ab3debe10277deed9d1b1cbbe9ce"
+source = "git+https://github.com/sigp/milagro_bls?tag=v1.1.0#32c9f9382fc73f8976a00aca9773e6a322bb2c9e"
 dependencies = [
  "hex 0.3.2",
  "lazy_static",
@@ -1305,6 +1305,7 @@ dependencies = [
 name = "eth2_key_derivation"
 version = "0.1.0"
 dependencies = [
+ "bls",
  "hex 0.3.2",
  "num-bigint-dig",
  "ring",
@@ -1317,6 +1318,7 @@ name = "eth2_keystore"
 version = "0.1.0"
 dependencies = [
  "bls",
+ "eth2_key_derivation",
  "eth2_ssz",
  "hex 0.3.2",
  "rand 0.7.3",
@@ -2743,8 +2745,8 @@ dependencies = [
 
 [[package]]
 name = "milagro_bls"
-version = "1.0.1"
-source = "git+https://github.com/sigp/milagro_bls?tag=v1.0.1#2ccdd4b517c1ab3debe10277deed9d1b1cbbe9ce"
+version = "1.1.0"
+source = "git+https://github.com/sigp/milagro_bls?tag=v1.1.0#32c9f9382fc73f8976a00aca9773e6a322bb2c9e"
 dependencies = [
  "amcl",
  "hex 0.4.2",
diff --git a/common/eth2_interop_keypairs/Cargo.toml b/common/eth2_interop_keypairs/Cargo.toml
index bc678f4e93..fb33be4eb0 100644
--- a/common/eth2_interop_keypairs/Cargo.toml
+++ b/common/eth2_interop_keypairs/Cargo.toml
@@ -11,7 +11,7 @@ lazy_static = "1.4.0"
 num-bigint = "0.2.6"
 eth2_hashing = "0.1.0"
 hex = "0.4.2"
-milagro_bls = { git = "https://github.com/sigp/milagro_bls", tag = "v1.0.1" }
+milagro_bls = { git = "https://github.com/sigp/milagro_bls", tag = "v1.1.0" }
 serde_yaml = "0.8.11"
 serde = "1.0.110"
 serde_derive = "1.0.110"
diff --git a/common/eth2_interop_keypairs/tests/generation.rs b/common/eth2_interop_keypairs/tests/generation.rs
index dfc6a9b410..02df8fe37e 100644
--- a/common/eth2_interop_keypairs/tests/generation.rs
+++ b/common/eth2_interop_keypairs/tests/generation.rs
@@ -53,6 +53,6 @@ fn reference_public_keys() {
             "Reference should be 48 bytes (public key size)"
         );
 
-        assert_eq!(pair.pk.as_bytes(), reference);
+        assert_eq!(pair.pk.as_bytes().to_vec(), reference);
     });
 }
diff --git a/crypto/bls/Cargo.toml b/crypto/bls/Cargo.toml
index 6c3d2a8f3e..ff894a7e08 100644
--- a/crypto/bls/Cargo.toml
+++ b/crypto/bls/Cargo.toml
@@ -5,7 +5,7 @@ authors = ["Paul Hauner <paul@paulhauner.com>"]
 edition = "2018"
 
 [dependencies]
-milagro_bls = { git = "https://github.com/sigp/milagro_bls", tag = "v1.0.1" }
+milagro_bls = { git = "https://github.com/sigp/milagro_bls", tag = "v1.1.0" }
 eth2_hashing = "0.1.0"
 hex = "0.4.2"
 rand = "0.7.3"
diff --git a/crypto/bls/src/aggregate_public_key.rs b/crypto/bls/src/aggregate_public_key.rs
index 628ed86d16..9fa65e96c7 100644
--- a/crypto/bls/src/aggregate_public_key.rs
+++ b/crypto/bls/src/aggregate_public_key.rs
@@ -43,7 +43,7 @@ impl AggregatePublicKey {
     }
 
     /// Returns the underlying point as compressed bytes.
-    pub fn as_bytes(&self) -> Vec<u8> {
+    pub fn as_bytes(&self) -> [u8; BLS_PUBLIC_KEY_BYTE_SIZE] {
         self.as_raw().as_bytes()
     }
 
@@ -54,7 +54,7 @@ impl AggregatePublicKey {
     /// Return a hex string representation of this key's bytes.
     #[cfg(test)]
     pub fn as_hex_string(&self) -> String {
-        serde_hex::encode(self.as_bytes())
+        serde_hex::encode(self.as_ssz_bytes())
     }
 }
 
@@ -71,7 +71,7 @@ impl Serialize for AggregatePublicKey {
     where
         S: Serializer,
     {
-        serializer.serialize_str(&hex_encode(self.as_bytes()))
+        serializer.serialize_str(&hex_encode(self.as_ssz_bytes()))
     }
 }
 
diff --git a/crypto/bls/src/aggregate_signature.rs b/crypto/bls/src/aggregate_signature.rs
index 176e61804f..3ad4fdddf2 100644
--- a/crypto/bls/src/aggregate_signature.rs
+++ b/crypto/bls/src/aggregate_signature.rs
@@ -1,5 +1,5 @@
 use super::*;
-use milagro_bls::{AggregateSignature as RawAggregateSignature, G2Point};
+use milagro_bls::AggregateSignature as RawAggregateSignature;
 use serde::de::{Deserialize, Deserializer};
 use serde::ser::{Serialize, Serializer};
 use serde_hex::{encode as hex_encode, PrefixedHexVisitor};
@@ -84,9 +84,9 @@ impl AggregateSignature {
     }
 
     /// Return AggregateSignature as bytes
-    pub fn as_bytes(&self) -> Vec<u8> {
+    pub fn as_bytes(&self) -> [u8; BLS_AGG_SIG_BYTE_SIZE] {
         if self.is_empty {
-            return vec![0; BLS_AGG_SIG_BYTE_SIZE];
+            return [0; BLS_AGG_SIG_BYTE_SIZE];
         }
         self.aggregate_signature.as_bytes()
     }
@@ -116,14 +116,6 @@ impl AggregateSignature {
         &self.aggregate_signature
     }
 
-    /// Returns the underlying signature.
-    pub fn from_point(point: G2Point) -> Self {
-        Self {
-            aggregate_signature: RawAggregateSignature { point },
-            is_empty: false,
-        }
-    }
-
     /// Returns if the AggregateSignature `is_empty`
     pub fn is_empty(&self) -> bool {
         self.is_empty
@@ -143,7 +135,7 @@ impl AggregateSignature {
     /// Return a hex string representation of the bytes of this signature.
     #[cfg(test)]
     pub fn as_hex_string(&self) -> String {
-        hex_encode(self.as_bytes())
+        hex_encode(self.as_ssz_bytes())
     }
 }
 
@@ -161,7 +153,7 @@ impl Serialize for AggregateSignature {
     where
         S: Serializer,
     {
-        serializer.serialize_str(&hex_encode(self.as_bytes()))
+        serializer.serialize_str(&hex_encode(self.as_ssz_bytes()))
     }
 }
 
diff --git a/crypto/bls/src/fake_aggregate_public_key.rs b/crypto/bls/src/fake_aggregate_public_key.rs
index cabd6862c4..4c25f21568 100644
--- a/crypto/bls/src/fake_aggregate_public_key.rs
+++ b/crypto/bls/src/fake_aggregate_public_key.rs
@@ -1,20 +1,18 @@
 use super::{PublicKey, BLS_PUBLIC_KEY_BYTE_SIZE};
 use hex::encode as hex_encode;
-use milagro_bls::G1Point;
 use serde::de::{Deserialize, Deserializer};
 use serde::ser::{Serialize, Serializer};
 use serde_hex::PrefixedHexVisitor;
 use ssz::{ssz_encode, Decode, DecodeError, Encode};
+use std::fmt;
 
 /// A BLS aggregate public key.
 ///
 /// This struct is a wrapper upon a base type and provides helper functions (e.g., SSZ
 /// serialization).
-#[derive(Debug, Clone, Default)]
+#[derive(Clone)]
 pub struct FakeAggregatePublicKey {
-    bytes: Vec<u8>,
-    /// Never used, only use for compatibility with "real" `AggregatePublicKey`.
-    pub point: G1Point,
+    bytes: [u8; BLS_PUBLIC_KEY_BYTE_SIZE],
 }
 
 impl FakeAggregatePublicKey {
@@ -24,8 +22,7 @@ impl FakeAggregatePublicKey {
 
     pub fn empty_signature() -> Self {
         Self {
-            bytes: vec![0; BLS_PUBLIC_KEY_BYTE_SIZE],
-            point: G1Point::new(),
+            bytes: [0; BLS_PUBLIC_KEY_BYTE_SIZE],
         }
     }
 
@@ -36,10 +33,9 @@ impl FakeAggregatePublicKey {
                 expected: BLS_PUBLIC_KEY_BYTE_SIZE,
             })
         } else {
-            Ok(Self {
-                bytes: bytes.to_vec(),
-                point: G1Point::new(),
-            })
+            let mut array = [0; BLS_PUBLIC_KEY_BYTE_SIZE];
+            array.copy_from_slice(&bytes);
+            Ok(Self { bytes: array })
         }
     }
 
@@ -54,8 +50,7 @@ impl FakeAggregatePublicKey {
     /// Creates a new all-zero's aggregate public key
     pub fn zero() -> Self {
         Self {
-            bytes: vec![0; BLS_PUBLIC_KEY_BYTE_SIZE],
-            point: G1Point::new(),
+            bytes: [0; BLS_PUBLIC_KEY_BYTE_SIZE],
         }
     }
 
@@ -63,10 +58,6 @@ impl FakeAggregatePublicKey {
         // No nothing.
     }
 
-    pub fn add_point(&mut self, _point: &G1Point) {
-        // No nothing.
-    }
-
     pub fn aggregate(_pks: &[&PublicKey]) -> Self {
         Self::new()
     }
@@ -74,7 +65,6 @@ impl FakeAggregatePublicKey {
     pub fn from_public_key(public_key: &PublicKey) -> Self {
         Self {
             bytes: public_key.as_bytes(),
-            point: public_key.point.clone(),
         }
     }
 
@@ -86,7 +76,7 @@ impl FakeAggregatePublicKey {
         self
     }
 
-    pub fn as_bytes(&self) -> Vec<u8> {
+    pub fn as_bytes(&self) -> [u8; BLS_PUBLIC_KEY_BYTE_SIZE] {
         self.bytes.clone()
     }
 }
@@ -120,6 +110,18 @@ impl<'de> Deserialize<'de> for FakeAggregatePublicKey {
     }
 }
 
+impl Default for FakeAggregatePublicKey {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl fmt::Debug for FakeAggregatePublicKey {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_fmt(format_args!("{:?}", self.bytes.to_vec()))
+    }
+}
+
 #[cfg(feature = "arbitrary")]
 impl arbitrary::Arbitrary for FakeAggregatePublicKey {
     fn arbitrary(u: &mut arbitrary::Unstructured<'_>) -> arbitrary::Result<Self> {
diff --git a/crypto/bls/src/fake_aggregate_signature.rs b/crypto/bls/src/fake_aggregate_signature.rs
index 3744f95792..2535cb13f5 100644
--- a/crypto/bls/src/fake_aggregate_signature.rs
+++ b/crypto/bls/src/fake_aggregate_signature.rs
@@ -2,21 +2,19 @@ use super::{
     fake_aggregate_public_key::FakeAggregatePublicKey, fake_public_key::FakePublicKey,
     fake_signature::FakeSignature, BLS_AGG_SIG_BYTE_SIZE,
 };
-use milagro_bls::G2Point;
 use serde::de::{Deserialize, Deserializer};
 use serde::ser::{Serialize, Serializer};
 use serde_hex::{encode as hex_encode, PrefixedHexVisitor};
 use ssz::{ssz_encode, Decode, DecodeError, Encode};
+use std::fmt;
 
 /// A BLS aggregate signature.
 ///
 /// This struct is a wrapper upon a base type and provides helper functions (e.g., SSZ
 /// serialization).
-#[derive(Debug, PartialEq, Clone, Default, Eq)]
+#[derive(Clone)]
 pub struct FakeAggregateSignature {
-    bytes: Vec<u8>,
-    /// Never used, only use for compatibility with "real" `AggregateSignature`.
-    pub point: G2Point,
+    bytes: [u8; BLS_AGG_SIG_BYTE_SIZE],
 }
 
 impl FakeAggregateSignature {
@@ -28,8 +26,7 @@ impl FakeAggregateSignature {
     /// Creates a new all-zero's signature
     pub fn zero() -> Self {
         Self {
-            bytes: vec![0; BLS_AGG_SIG_BYTE_SIZE],
-            point: G2Point::new(),
+            bytes: [0; BLS_AGG_SIG_BYTE_SIZE],
         }
     }
 
@@ -79,7 +76,13 @@ impl FakeAggregateSignature {
     pub fn from_signature(signature: &FakeSignature) -> Self {
         Self {
             bytes: signature.as_bytes(),
-            point: signature.point.clone(),
+        }
+    }
+
+    /// Creates a new empty FakeAggregateSignature
+    pub fn empty_signature() -> Self {
+        Self {
+            bytes: [0u8; BLS_AGG_SIG_BYTE_SIZE],
         }
     }
 
@@ -91,14 +94,13 @@ impl FakeAggregateSignature {
                 expected: BLS_AGG_SIG_BYTE_SIZE,
             })
         } else {
-            Ok(Self {
-                bytes: bytes.to_vec(),
-                point: G2Point::new(),
-            })
+            let mut array = [0u8; BLS_AGG_SIG_BYTE_SIZE];
+            array.copy_from_slice(bytes);
+            Ok(Self { bytes: array })
         }
     }
 
-    pub fn as_bytes(&self) -> Vec<u8> {
+    pub fn as_bytes(&self) -> [u8; BLS_AGG_SIG_BYTE_SIZE] {
         self.bytes.clone()
     }
 }
@@ -132,6 +134,26 @@ impl<'de> Deserialize<'de> for FakeAggregateSignature {
     }
 }
 
+impl fmt::Debug for FakeAggregateSignature {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_fmt(format_args!("{:?}", self.bytes.to_vec()))
+    }
+}
+
+impl PartialEq for FakeAggregateSignature {
+    fn eq(&self, other: &FakeAggregateSignature) -> bool {
+        ssz_encode(self) == ssz_encode(other)
+    }
+}
+
+impl Eq for FakeAggregateSignature {}
+
+impl Default for FakeAggregateSignature {
+    fn default() -> Self {
+        Self::zero()
+    }
+}
+
 #[cfg(feature = "arbitrary")]
 impl arbitrary::Arbitrary for FakeAggregateSignature {
     fn arbitrary(u: &mut arbitrary::Unstructured<'_>) -> arbitrary::Result<Self> {
diff --git a/crypto/bls/src/fake_public_key.rs b/crypto/bls/src/fake_public_key.rs
index 32852b085c..02b59812fa 100644
--- a/crypto/bls/src/fake_public_key.rs
+++ b/crypto/bls/src/fake_public_key.rs
@@ -1,5 +1,4 @@
 use super::{SecretKey, BLS_PUBLIC_KEY_BYTE_SIZE};
-use milagro_bls::G1Point;
 use milagro_bls::PublicKey as RawPublicKey;
 use serde::de::{Deserialize, Deserializer};
 use serde::ser::{Serialize, Serializer};
@@ -13,11 +12,9 @@ use std::hash::{Hash, Hasher};
 ///
 /// This struct is a wrapper upon a base type and provides helper functions (e.g., SSZ
 /// serialization).
-#[derive(Clone, Eq)]
+#[derive(Clone)]
 pub struct FakePublicKey {
-    bytes: Vec<u8>,
-    /// Never used, only use for compatibility with "real" `PublicKey`.
-    pub point: G1Point,
+    bytes: [u8; BLS_PUBLIC_KEY_BYTE_SIZE],
 }
 
 impl FakePublicKey {
@@ -28,39 +25,52 @@ impl FakePublicKey {
     pub fn from_raw(raw: RawPublicKey) -> Self {
         Self {
             bytes: raw.clone().as_bytes(),
-            point: G1Point::new(),
         }
     }
 
     /// Creates a new all-zero's public key
     pub fn zero() -> Self {
         Self {
-            bytes: vec![0; BLS_PUBLIC_KEY_BYTE_SIZE],
-            point: G1Point::new(),
+            bytes: [0; BLS_PUBLIC_KEY_BYTE_SIZE],
         }
     }
 
     /// Returns the underlying point as compressed bytes.
-    pub fn as_bytes(&self) -> Vec<u8> {
+    pub fn as_bytes(&self) -> [u8; BLS_PUBLIC_KEY_BYTE_SIZE] {
         self.bytes.clone()
     }
 
     /// Converts compressed bytes to FakePublicKey
     pub fn from_bytes(bytes: &[u8]) -> Result<Self, DecodeError> {
-        Ok(Self {
-            bytes: bytes.to_vec(),
-            point: G1Point::new(),
-        })
+        if bytes.len() != BLS_PUBLIC_KEY_BYTE_SIZE {
+            Err(DecodeError::InvalidByteLength {
+                len: bytes.len(),
+                expected: BLS_PUBLIC_KEY_BYTE_SIZE,
+            })
+        } else {
+            let mut array = [0u8; BLS_PUBLIC_KEY_BYTE_SIZE];
+            array.copy_from_slice(bytes);
+            Ok(Self { bytes: array })
+        }
     }
 
     /// Returns the FakePublicKey as (x, y) bytes
-    pub fn as_uncompressed_bytes(&self) -> Vec<u8> {
-        self.as_bytes()
+    pub fn as_uncompressed_bytes(&self) -> [u8; BLS_PUBLIC_KEY_BYTE_SIZE * 2] {
+        [0u8; BLS_PUBLIC_KEY_BYTE_SIZE * 2]
     }
 
     /// Converts (x, y) bytes to FakePublicKey
     pub fn from_uncompressed_bytes(bytes: &[u8]) -> Result<Self, DecodeError> {
-        Self::from_bytes(bytes)
+        if bytes.len() != BLS_PUBLIC_KEY_BYTE_SIZE * 2 {
+            Err(DecodeError::InvalidByteLength {
+                len: bytes.len(),
+                expected: BLS_PUBLIC_KEY_BYTE_SIZE * 2,
+            })
+        } else {
+            let mut array = [0u8; BLS_PUBLIC_KEY_BYTE_SIZE];
+            array.copy_from_slice(bytes);
+            Ok(Self { bytes: array })
+        }
     }
 
     /// Returns the last 6 bytes of the SSZ encoding of the public key, as a hex string.
@@ -83,14 +93,6 @@ impl FakePublicKey {
     pub fn as_raw(&self) -> &Self {
         self
     }
-
-    pub fn as_point(&self) -> &G1Point {
-        &self.point
-    }
-
-    pub fn into_point(self) -> G1Point {
-        self.point
-    }
 }
 
 impl fmt::Display for FakePublicKey {
@@ -121,7 +123,7 @@ impl Serialize for FakePublicKey {
     where
         S: Serializer,
     {
-        serializer.serialize_str(&hex_encode(self.as_bytes()))
+        serializer.serialize_str(&hex_encode(self.as_ssz_bytes()))
     }
 }
 
@@ -143,6 +145,8 @@ impl PartialEq for FakePublicKey {
     }
 }
 
+impl Eq for FakePublicKey {}
+
 impl Hash for FakePublicKey {
     /// Note: this is distinct from consensus serialization, it will produce a different hash.
     ///
diff --git a/crypto/bls/src/fake_signature.rs b/crypto/bls/src/fake_signature.rs
index df77a3d935..2fcb669011 100644
--- a/crypto/bls/src/fake_signature.rs
+++ b/crypto/bls/src/fake_signature.rs
@@ -1,21 +1,19 @@
 use super::{PublicKey, SecretKey, BLS_SIG_BYTE_SIZE};
 use hex::encode as hex_encode;
-use milagro_bls::G2Point;
 use serde::de::{Deserialize, Deserializer};
 use serde::ser::{Serialize, Serializer};
 use serde_hex::PrefixedHexVisitor;
 use ssz::{ssz_encode, Decode, DecodeError, Encode};
+use std::fmt;
 
 /// A single BLS signature.
 ///
 /// This struct is a wrapper upon a base type and provides helper functions (e.g., SSZ
 /// serialization).
-#[derive(Debug, PartialEq, Clone, Eq)]
+#[derive(Clone)]
 pub struct FakeSignature {
-    bytes: Vec<u8>,
+    bytes: [u8; BLS_SIG_BYTE_SIZE],
     is_empty: bool,
-    /// Never used, only use for compatibility with "real" `Signature`.
-    pub point: G2Point,
 }
 
 impl FakeSignature {
@@ -27,9 +25,8 @@ impl FakeSignature {
     /// Creates a new all-zero's signature
     pub fn zero() -> Self {
         Self {
-            bytes: vec![0; BLS_SIG_BYTE_SIZE],
+            bytes: [0; BLS_SIG_BYTE_SIZE],
             is_empty: true,
-            point: G2Point::new(),
         }
     }
 
@@ -66,15 +63,16 @@ impl FakeSignature {
             })
         } else {
             let is_empty = bytes.iter().all(|x| *x == 0);
+            let mut array = [0u8; BLS_SIG_BYTE_SIZE];
+            array.copy_from_slice(bytes);
             Ok(Self {
-                bytes: bytes.to_vec(),
+                bytes: array,
                 is_empty,
-                point: G2Point::new(),
             })
         }
     }
 
-    pub fn as_bytes(&self) -> Vec<u8> {
+    pub fn as_bytes(&self) -> [u8; BLS_SIG_BYTE_SIZE] {
         self.bytes.clone()
     }
 
@@ -93,6 +91,24 @@ impl_ssz!(FakeSignature, BLS_SIG_BYTE_SIZE, "FakeSignature");
 
 impl_tree_hash!(FakeSignature, BLS_SIG_BYTE_SIZE);
 
+impl fmt::Debug for FakeSignature {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_fmt(format_args!(
+            "{:?}, {:?}",
+            self.bytes.to_vec(),
+            self.is_empty()
+        ))
+    }
+}
+
+impl PartialEq for FakeSignature {
+    fn eq(&self, other: &FakeSignature) -> bool {
+        self.bytes.to_vec() == other.bytes.to_vec()
+    }
+}
+
+impl Eq for FakeSignature {}
+
 impl Serialize for FakeSignature {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
diff --git a/crypto/bls/src/lib.rs b/crypto/bls/src/lib.rs
index 23cc6a6eaa..dff6403d16 100644
--- a/crypto/bls/src/lib.rs
+++ b/crypto/bls/src/lib.rs
@@ -4,8 +4,8 @@ extern crate ssz;
 #[macro_use]
 mod macros;
 mod keypair;
-mod plain_text;
 mod public_key_bytes;
+mod secret_hash;
 mod secret_key;
 mod signature_bytes;
 mod signature_set;
@@ -14,8 +14,7 @@ pub use crate::keypair::Keypair;
 pub use crate::public_key_bytes::PublicKeyBytes;
 pub use crate::secret_key::SecretKey;
 pub use crate::signature_bytes::SignatureBytes;
-pub use milagro_bls::{compress_g2, hash_to_curve_g2};
-pub use plain_text::PlainText;
+pub use secret_hash::SecretHash;
 pub use signature_set::{verify_signature_sets, SignatureSet};
 
 #[cfg(feature = "arbitrary")]
diff --git a/crypto/bls/src/macros.rs b/crypto/bls/src/macros.rs
index a7b1a99bab..8a2f386e51 100644
--- a/crypto/bls/src/macros.rs
+++ b/crypto/bls/src/macros.rs
@@ -14,7 +14,7 @@ macro_rules! impl_ssz {
             }
 
             fn ssz_append(&self, buf: &mut Vec<u8>) {
-                buf.append(&mut self.as_bytes())
+                buf.extend_from_slice(&self.as_bytes())
             }
         }
 
diff --git a/crypto/bls/src/public_key.rs b/crypto/bls/src/public_key.rs
index 98eaf467ac..c9b454c37f 100644
--- a/crypto/bls/src/public_key.rs
+++ b/crypto/bls/src/public_key.rs
@@ -1,5 +1,5 @@
 use super::{SecretKey, BLS_PUBLIC_KEY_BYTE_SIZE};
-use milagro_bls::{G1Point, PublicKey as RawPublicKey};
+use milagro_bls::PublicKey as RawPublicKey;
 use serde::de::{Deserialize, Deserializer};
 use serde::ser::{Serialize, Serializer};
 use serde_hex::{encode as hex_encode, PrefixedHexVisitor};
@@ -29,18 +29,8 @@ impl PublicKey {
         &self.0
     }
 
-    /// Consumes self and returns the underlying signature.
-    pub fn as_point(&self) -> &G1Point {
-        &self.0.point
-    }
-
-    /// Consumes self and returns the underlying signature.
-    pub fn into_point(self) -> G1Point {
-        self.0.point
-    }
-
     /// Returns the underlying point as compressed bytes.
-    pub fn as_bytes(&self) -> Vec<u8> {
+    pub fn as_bytes(&self) -> [u8; BLS_PUBLIC_KEY_BYTE_SIZE] {
         self.as_raw().as_bytes()
     }
 
@@ -54,7 +44,7 @@ impl PublicKey {
     }
 
     /// Returns the PublicKey as (x, y) bytes
-    pub fn as_uncompressed_bytes(&self) -> Vec<u8> {
+    pub fn as_uncompressed_bytes(&self) -> [u8; BLS_PUBLIC_KEY_BYTE_SIZE * 2] {
         RawPublicKey::as_uncompressed_bytes(&mut self.0.clone())
     }
 
@@ -109,7 +99,7 @@ impl Serialize for PublicKey {
     where
         S: Serializer,
     {
-        serializer.serialize_str(&hex_encode(self.as_raw().as_bytes()))
+        serializer.serialize_str(&hex_encode(self.as_ssz_bytes()))
     }
 }
 
diff --git a/crypto/eth2_key_derivation/src/secret_hash.rs b/crypto/bls/src/secret_hash.rs
similarity index 56%
rename from crypto/eth2_key_derivation/src/secret_hash.rs
rename to crypto/bls/src/secret_hash.rs
index 0d9cfac110..c1d92d00db 100644
--- a/crypto/eth2_key_derivation/src/secret_hash.rs
+++ b/crypto/bls/src/secret_hash.rs
@@ -1,15 +1,15 @@
-use crate::derived_key::HASH_SIZE;
+use super::BLS_SECRET_KEY_BYTE_SIZE;
 use zeroize::Zeroize;
 
 /// Provides a wrapper around a `[u8; HASH_SIZE]` that implements `Zeroize` on `Drop`.
 #[derive(Zeroize)]
 #[zeroize(drop)]
-pub struct SecretHash([u8; HASH_SIZE]);
+pub struct SecretHash([u8; BLS_SECRET_KEY_BYTE_SIZE]);
 
 impl SecretHash {
     /// Instantiates `Self` with all zeros.
     pub fn zero() -> Self {
-        Self([0; HASH_SIZE])
+        Self([0; BLS_SECRET_KEY_BYTE_SIZE])
     }
 
     /// Returns a reference to the underlying bytes.
@@ -22,3 +22,15 @@ impl SecretHash {
         &mut self.0
     }
 }
+
+impl From<[u8; BLS_SECRET_KEY_BYTE_SIZE]> for SecretHash {
+    fn from(array: [u8; BLS_SECRET_KEY_BYTE_SIZE]) -> Self {
+        Self(array)
+    }
+}
+
+impl AsRef<[u8]> for SecretHash {
+    fn as_ref(&self) -> &[u8] {
+        &self.0
+    }
+}
diff --git a/crypto/bls/src/secret_key.rs b/crypto/bls/src/secret_key.rs
index 3cb0cd8b08..3d03805ea1 100644
--- a/crypto/bls/src/secret_key.rs
+++ b/crypto/bls/src/secret_key.rs
@@ -1,6 +1,6 @@
 extern crate rand;
 
-use crate::PlainText;
+use crate::SecretHash;
 use milagro_bls::SecretKey as RawSecretKey;
 use ssz::DecodeError;
 
@@ -21,12 +21,12 @@ impl SecretKey {
         Self(raw)
     }
 
-    /// Returns the secret key as a byte array (wrapped in `PlainText` wrapper so it is zeroized on
+    /// Returns the secret key as a byte array (wrapped in `SecretHash` wrapper so it is zeroized on
     /// `Drop`).
     ///
     /// Extreme care should be taken not to leak these bytes as they are the unencrypted secret
     /// key.
-    pub fn as_bytes(&self) -> PlainText {
+    pub fn as_bytes(&self) -> SecretHash {
         self.as_raw().as_bytes().into()
     }
 
@@ -63,6 +63,6 @@ mod tests {
         let bytes = original.as_bytes();
         let decoded = SecretKey::from_bytes(bytes.as_ref()).unwrap();
 
-        assert!(original.as_bytes() == decoded.as_bytes());
+        assert!(original.as_bytes().as_ref().to_vec() == decoded.as_bytes().as_ref().to_vec());
     }
 }
diff --git a/crypto/bls/src/signature.rs b/crypto/bls/src/signature.rs
index 73de59bf9a..5a2bea773a 100644
--- a/crypto/bls/src/signature.rs
+++ b/crypto/bls/src/signature.rs
@@ -40,7 +40,7 @@ impl Signature {
     /// Returns a new empty signature.
     pub fn empty_signature() -> Self {
         // Set RawSignature = infinity
-        let mut empty: Vec<u8> = vec![0; BLS_SIG_BYTE_SIZE];
+        let mut empty = [0u8; BLS_SIG_BYTE_SIZE];
         empty[0] += u8::pow(2, 6) + u8::pow(2, 7);
         Signature {
             signature: RawSignature::from_bytes(&empty).unwrap(),
@@ -49,9 +49,9 @@ impl Signature {
     }
 
     // Converts a BLS Signature to bytes
-    pub fn as_bytes(&self) -> Vec<u8> {
+    pub fn as_bytes(&self) -> [u8; BLS_SIG_BYTE_SIZE] {
         if self.is_empty {
-            return vec![0; 96];
+            return [0u8; BLS_SIG_BYTE_SIZE];
         }
         self.signature.as_bytes()
     }
@@ -80,7 +80,7 @@ impl Signature {
     /// Display a signature as a hex string of its bytes.
     #[cfg(test)]
     pub fn as_hex_string(&self) -> String {
-        hex_encode(self.as_bytes())
+        hex_encode(self.as_ssz_bytes())
     }
 }
 
@@ -148,10 +148,10 @@ mod tests {
     }
 
     #[test]
-    pub fn test_empty_signature() {
+    pub fn test_infinity_signature() {
         let sig = Signature::empty_signature();
 
-        let sig_as_bytes: Vec<u8> = sig.as_raw().as_bytes();
+        let sig_as_bytes = sig.as_raw().as_bytes();
 
         assert_eq!(sig_as_bytes.len(), BLS_SIG_BYTE_SIZE);
         for (i, one_byte) in sig_as_bytes.iter().enumerate() {
@@ -162,4 +162,13 @@ mod tests {
             }
         }
     }
+
+    #[test]
+    pub fn test_empty_signature() {
+        let sig = Signature::empty_signature();
+
+        let sig_as_bytes = sig.as_bytes().to_vec();
+
+        assert_eq!(sig_as_bytes, vec![0u8; BLS_SIG_BYTE_SIZE]);
+    }
 }
diff --git a/crypto/eth2_key_derivation/Cargo.toml b/crypto/eth2_key_derivation/Cargo.toml
index b912c58a10..c0607fff91 100644
--- a/crypto/eth2_key_derivation/Cargo.toml
+++ b/crypto/eth2_key_derivation/Cargo.toml
@@ -11,6 +11,7 @@ rust-crypto = "0.2.36"
 zeroize = { version = "1.0.0", features = ["zeroize_derive"] }
 num-bigint-dig = { version = "0.6.0", features = ["zeroize"] }
 ring = "0.16.9"
+bls = { path = "../bls" }
 
 [dev-dependencies]
 hex = "0.3"
diff --git a/crypto/eth2_key_derivation/src/derived_key.rs b/crypto/eth2_key_derivation/src/derived_key.rs
index a8a0cf7df1..ecc31e64b4 100644
--- a/crypto/eth2_key_derivation/src/derived_key.rs
+++ b/crypto/eth2_key_derivation/src/derived_key.rs
@@ -1,6 +1,4 @@
-use crate::{
-    lamport_secret_key::LamportSecretKey, secret_bytes::SecretBytes, secret_hash::SecretHash,
-};
+use crate::{lamport_secret_key::LamportSecretKey, secret_bytes::SecretBytes, SecretHash};
 use crypto::{digest::Digest, sha2::Sha256};
 use num_bigint_dig::BigUint;
 use ring::hkdf::{KeyType, Prk, Salt, HKDF_SHA256};
diff --git a/crypto/eth2_key_derivation/src/lib.rs b/crypto/eth2_key_derivation/src/lib.rs
index f6ed44c4df..763f8fe04c 100644
--- a/crypto/eth2_key_derivation/src/lib.rs
+++ b/crypto/eth2_key_derivation/src/lib.rs
@@ -3,7 +3,9 @@
 
 mod derived_key;
 mod lamport_secret_key;
+mod plain_text;
 mod secret_bytes;
-mod secret_hash;
 
+pub use bls::SecretHash;
 pub use derived_key::DerivedKey;
+pub use plain_text::PlainText;
diff --git a/crypto/bls/src/plain_text.rs b/crypto/eth2_key_derivation/src/plain_text.rs
similarity index 100%
rename from crypto/bls/src/plain_text.rs
rename to crypto/eth2_key_derivation/src/plain_text.rs
diff --git a/crypto/eth2_keystore/Cargo.toml b/crypto/eth2_keystore/Cargo.toml
index 89123379ef..43573961be 100644
--- a/crypto/eth2_keystore/Cargo.toml
+++ b/crypto/eth2_keystore/Cargo.toml
@@ -17,6 +17,6 @@ hex = "0.3"
 bls = { path = "../bls" }
 eth2_ssz = { path = "../../consensus/ssz" }
 serde_json = "1.0.41"
-
+eth2_key_derivation = { path = "../eth2_key_derivation" }
 [dev-dependencies]
 tempfile = "3.1.0"
diff --git a/crypto/eth2_keystore/src/keystore.rs b/crypto/eth2_keystore/src/keystore.rs
index 04c0655a65..8d68265a7d 100644
--- a/crypto/eth2_keystore/src/keystore.rs
+++ b/crypto/eth2_keystore/src/keystore.rs
@@ -6,10 +6,10 @@ use crate::json_keystore::{
     Aes128Ctr, ChecksumModule, Cipher, CipherModule, Crypto, EmptyMap, EmptyString, JsonKeystore,
     Kdf, KdfModule, Scrypt, Sha256Checksum, Version,
 };
-use crate::PlainText;
 use crate::Uuid;
-use bls::{Keypair, PublicKey, SecretKey};
+use bls::{Keypair, PublicKey, SecretHash, SecretKey};
 use crypto::{digest::Digest, sha2::Sha256};
+use eth2_key_derivation::PlainText;
 use rand::prelude::*;
 use serde::{Deserialize, Serialize};
 use ssz::DecodeError;
@@ -136,7 +136,7 @@ impl Keystore {
         uuid: Uuid,
         path: String,
     ) -> Result<Self, Error> {
-        let secret: PlainText = keypair.sk.as_bytes();
+        let secret: SecretHash = keypair.sk.as_bytes();
 
         let (cipher_text, checksum) = encrypt(secret.as_bytes(), password, &kdf, &cipher)?;
 
diff --git a/crypto/eth2_keystore/src/lib.rs b/crypto/eth2_keystore/src/lib.rs
index 93dbabe5de..385b1950b6 100644
--- a/crypto/eth2_keystore/src/lib.rs
+++ b/crypto/eth2_keystore/src/lib.rs
@@ -6,7 +6,8 @@ mod keystore;
 
 pub mod json_keystore;
 
-pub use bls::PlainText;
+pub use bls::SecretHash;
+pub use eth2_key_derivation::PlainText;
 pub use keystore::{
     decrypt, default_kdf, encrypt, keypair_from_secret, Error, Keystore, KeystoreBuilder, DKLEN,
     HASH_SIZE, IV_SIZE, SALT_SIZE,
diff --git a/lighthouse/tests/account_manager.rs b/lighthouse/tests/account_manager.rs
index 31a02786d4..b8daa2b726 100644
--- a/lighthouse/tests/account_manager.rs
+++ b/lighthouse/tests/account_manager.rs
@@ -369,7 +369,7 @@ fn validator_create() {
 fn write_legacy_keypair<P: AsRef<Path>>(name: &str, dir: P) -> Keypair {
     let keypair = Keypair::random();
 
-    let mut keypair_bytes = keypair.pk.as_bytes();
+    let mut keypair_bytes = keypair.pk.as_bytes().to_vec();
     keypair_bytes.extend_from_slice(keypair.sk.as_bytes().as_ref());
 
     fs::write(dir.as_ref().join(name), &keypair_bytes).unwrap();
diff --git a/testing/ef_tests/src/cases/bls_aggregate_sigs.rs b/testing/ef_tests/src/cases/bls_aggregate_sigs.rs
index 22fa197df6..561c7bc643 100644
--- a/testing/ef_tests/src/cases/bls_aggregate_sigs.rs
+++ b/testing/ef_tests/src/cases/bls_aggregate_sigs.rs
@@ -29,7 +29,7 @@ impl Case for BlsAggregateSigs {
             hex::decode(&self.output[2..])
                 .map_err(|e| Error::FailedToParseTest(format!("{:?}", e)))?,
         );
-        let aggregate_signature = Ok(aggregate_signature.as_bytes());
+        let aggregate_signature = Ok(aggregate_signature.as_bytes().to_vec());
 
         compare_result::<Vec<u8>, Vec<u8>>(&aggregate_signature, &output_bytes)
     }
diff --git a/testing/ef_tests/src/cases/bls_sign_msg.rs b/testing/ef_tests/src/cases/bls_sign_msg.rs
index b985a2d399..2662746995 100644
--- a/testing/ef_tests/src/cases/bls_sign_msg.rs
+++ b/testing/ef_tests/src/cases/bls_sign_msg.rs
@@ -33,6 +33,6 @@ impl Case for BlsSign {
         let decoded = hex::decode(&self.output[2..])
             .map_err(|e| Error::FailedToParseTest(format!("{:?}", e)))?;
 
-        compare_result::<Vec<u8>, Vec<u8>>(&Ok(signature.as_bytes()), &Some(decoded))
+        compare_result::<Vec<u8>, Vec<u8>>(&Ok(signature.as_bytes().to_vec()), &Some(decoded))
     }
 }