diff --git a/src/crypto.zig b/src/crypto.zig
index 1a8c8d0..7d15d16 100644
--- a/src/crypto.zig
+++ b/src/crypto.zig
@@ -15,7 +15,7 @@ const RANDOM = @import("crypto/random.zig");
 //
 
 pub const PartialEngine = struct {
-    aes_cbc256: ? AES.CBC256_Implementation = null,
+    aes_cbc256: ? AES.CBC256.Implementation = null,
     ed25519:    ? ED25519.Implementation    = null,
     hkdf:       ? HKDF.Implementation       = null,
     hmac:       ? HMAC.Implementation       = null,
@@ -26,7 +26,7 @@ pub const PartialEngine = struct {
 };
 
 pub const Engine = struct {
-    aes_cbc256: AES.CBC256_Implementation,
+    aes_cbc256: AES.CBC256.Implementation,
     ed25519:    ED25519.Implementation,
     hkdf:       HKDF.Implementation,
     hmac:       HMAC.Implementation,
@@ -45,18 +45,15 @@ pub const Engine = struct {
 // function and its sub-structs.
 pub fn resolveEngine(comptime provider: PartialEngine) Engine {
 
-    // Used by other engine components
-    const randomImpl = provider.random orelse RANDOM.defaultImplementation;
-
     return .{
-        .aes_cbc256 = provider.aes_cbc256 orelse AES.CBC256_DefaultImplementation,
-        .ed25519    = provider.ed25519    orelse ED25519.defaultImplementation(randomImpl),
-        .hkdf       = provider.hkdf       orelse HKDF.DefaultImplementation,
-        .hmac       = provider.hmac       orelse HMAC.DefaultImplementation,
-        .sha256     = provider.sha256     orelse SHA256.DefaultImplementation,
-        .sha512     = provider.sha512     orelse SHA512.DefaultImplementation,
-        .x25519     = provider.x25519     orelse X25519.DefaultImplementation,
-        .random     = randomImpl,
+        .aes_cbc256 = provider.aes_cbc256 orelse AES.CBC256.defaultImplementation,
+        .ed25519    = provider.ed25519    orelse ED25519.defaultImplementation,
+        .hkdf       = provider.hkdf       orelse HKDF.defaultImplementation,
+        .hmac       = provider.hmac       orelse HMAC.defaultImplementation,
+        .sha256     = provider.sha256     orelse SHA256.defaultImplementation,
+        .sha512     = provider.sha512     orelse SHA512.defaultImplementation,
+        .x25519     = provider.x25519     orelse X25519.defaultImplementation,
+        .random     = provider.random     orelse RANDOM.defaultImplementation,
     };
 }
 
diff --git a/src/crypto/aes.zig b/src/crypto/aes.zig
index e948313..1498678 100644
--- a/src/crypto/aes.zig
+++ b/src/crypto/aes.zig
@@ -1,30 +1,34 @@
-pub const block_size = 16;
-pub const key_size = 32;
+pub const CBC256 = struct {
+    
+    pub const block_size = 16;
+    pub const key_size = 32;
 
-pub const CBC256_Implementation = struct {
+    pub const Implementation = struct {
 
-    // NOTE: data should be padded to make its length be a multiple of BLOCK_SIZE
-    encrypt:  *const fn (key: *const [key_size]u8, iv: *const [block_size]u8, data: *const []u8) void,
-    decrypt: *const fn (key: *const [key_size]u8, iv: *const [block_size]u8, data: *const []u8) void,
+        // NOTE: data should be padded to make its length be a multiple of BLOCK_SIZE
+        encrypt:  *const fn (key: *const [key_size]u8, iv: *const [block_size]u8, data: *const []u8) void,
+        decrypt: *const fn (key: *const [key_size]u8, iv: *const [block_size]u8, data: *const []u8) void,
+    };
+
+    // TODO
+
+    // Zig stdlib seems to provide no support for AES CBC265
+    // It may need some custom implementation or another library
+
+    fn encrypt(key: *const [key_size]u8, iv: *const [block_size]u8, data: *const []u8) void {
+        _ = key;
+        _ = iv;
+        _ = data;
+    }
+    fn decrypt(key: *const [key_size]u8, iv: *const [block_size]u8, data: *const []u8) void {
+        _ = key;
+        _ = iv;
+        _ = data;
+    }
+
+    pub const defaultImplementation: Implementation =  .{
+        .decrypt = decrypt,
+        .encrypt = encrypt,
+    };
 };
 
-// TODO
-
-// Zig stdlib seems to provide no support for AES CBC265
-// It may need some custom implementation or another library
-
-fn encrypt(key: *const [key_size]u8, iv: *const [block_size]u8, data: *const []u8) void {
-    _ = key;
-    _ = iv;
-    _ = data;
-}
-fn decrypt(key: *const [key_size]u8, iv: *const [block_size]u8, data: *const []u8) void {
-    _ = key;
-    _ = iv;
-    _ = data;
-}
-
-pub const CBC256_DefaultImplementation: CBC256_Implementation =  .{
-    .decrypt = decrypt,
-    .encrypt = encrypt,
-};