diff --git a/CHANGELOG.md b/CHANGELOG.md
index fe2072b..1fd116a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,9 +2,13 @@
 
 All changes made to this project will be noted in this file.
 
-### 0.3.1
+### 0.4.0
 
-- Reduced branching in `rcrypt::verify`
+- `rcrypt::hash` now directly produces hashes instead of encoding into base64 and back
+- (BREAKING): `RcryptError::BcryptError` was removed
+- (BREAKING): `RcryptError::BadCost` is now `BadDecodedCost`
+- New variants in `RcryptError`: `DisallowedCost`, `BadPassword`, `RngError` and `BadSalt`
+- `rcrypt` now uses its own `bcrypt` implementation
 
 ## 0.3.0
 
diff --git a/Cargo.toml b/Cargo.toml
index 5c5fe4f..99b495f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "rcrypt"
-version = "0.3.1"
+version = "0.4.0-alpha.1"
 edition = "2021"
 authors = ["Sayan Nandan <nandansayan@outlook.com>"]
 license = "Apache-2.0"
diff --git a/src/algorithms.rs b/src/algorithms.rs
index f6e61d3..91630e4 100644
--- a/src/algorithms.rs
+++ b/src/algorithms.rs
@@ -67,7 +67,7 @@ pub fn encode_into_bmcf(input: &str) -> RcryptResult<Vec<u8>> {
     // the cost
     let cost: u8 = parts[1]
         .parse()
-        .map_err(|_| RcryptError::BadCost(parts[1].to_owned()))?;
+        .map_err(|_| RcryptError::BadDecodedCost(parts[1].to_owned()))?;
     // the salt (22-bytes)
     let salt = &parts[2][0..22];
     // the digest (31-bytes)
@@ -114,7 +114,7 @@ pub fn decode_into_mcf(input: &[u8]) -> RcryptResult<String> {
     // get cost
     let costint = header_octet - scheme_id;
     if costint > 31 {
-        return Err(RcryptError::BadCost(format!(
+        return Err(RcryptError::BadDecodedCost(format!(
             "expected cost is 4-31, found {}",
             costint
         )));
@@ -242,7 +242,7 @@ pub fn rcrypt_verify(password: &[u8], hash: &[u8]) -> RcryptResult<bool> {
     // the cost
     let costint = header_octet - scheme_id;
     if (costint as u32) > MAX_COST || (costint as u32) < MIN_COST {
-        return Err(RcryptError::BadCost(format!(
+        return Err(RcryptError::BadDecodedCost(format!(
             "Expected cost in {min}-{max}, got {cost}",
             min = MIN_COST,
             max = MAX_COST,
diff --git a/src/lib.rs b/src/lib.rs
index 82b6279..b55aa4d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -98,7 +98,7 @@ mod error {
         /// The hash prefix is unsupported
         UnsupportedHashPrefix(u8),
         /// The cost of the hash is incorrect
-        BadCost(String),
+        BadDecodedCost(String),
         /// The cost is not allowed
         DisallowedCost(u32),
         /// Unknown scheme
@@ -133,7 +133,7 @@ mod error {
     impl fmt::Display for RcryptError {
         fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
             match self {
-                RcryptError::BadCost(c) => write!(f, "failed to decode cost: {}", c),
+                RcryptError::BadDecodedCost(c) => write!(f, "failed to decode cost: {}", c),
                 RcryptError::Base64Error(e) => write!(f, "base64 decode error: {}", e),
                 RcryptError::CorruptedHash(e) => write!(f, "corrupted hash: {}", e),
                 RcryptError::UnknownScheme(e) => write!(f, "unknown scheme: {}", e),