diff --git a/src/crypto/ed25519.zig b/src/crypto/ed25519.zig
index 889f713..ea3a019 100644
--- a/src/crypto/ed25519.zig
+++ b/src/crypto/ed25519.zig
@@ -5,37 +5,37 @@ const Ed25519 = @import("std").crypto.sign.Ed25519;
 // Random number generation
 const rngProvider = @import("random.zig").Implementation;
 
-pub const secret_key_size: comptime_int = Ed25519.SecretKey.encoded_length;
-pub const public_key_size: comptime_int = Ed25519.PublicKey.encoded_length;
-pub const signature_size : comptime_int = Ed25519.Signature.encoded_length;
+pub const secret_key_length: comptime_int = Ed25519.SecretKey.encoded_length;
+pub const public_key_length: comptime_int = Ed25519.PublicKey.encoded_length;
+pub const signature_length : comptime_int = Ed25519.Signature.encoded_length;
+pub const seed_length : comptime_int = Ed25519.Signature.encoded_length;
 
 pub const Implementation = struct {
 
-    generateKeys: *const fn (pubkey_buffer: *[public_key_size]u8, privkey_buffer: *[secret_key_size]u8, rng: rngProvider) CryptoError!void,
-    sign: *const fn (key: *const [secret_key_size]u8, data: []const u8, signature_out: *const [signature_size]u8) CryptoError!void,
-    verify: *const fn (key: *const [public_key_size]u8, signature: *const [signature_size]u8, data: []const u8) CryptoError!void,
+    generateKeys: *const fn (pubkey_buffer: ?*[public_key_length]u8, privkey_buffer: *[secret_key_length]u8, rng: rngProvider) CryptoError!void,
+    sign: *const fn (key: *const [secret_key_length]u8, data: []const u8, signature_out: *const [signature_length]u8) CryptoError!void,
+    verify: *const fn (key: *const [public_key_length]u8, signature: *const [signature_length]u8, data: []const u8) CryptoError!void,
 };
 
 
-pub fn generateKeys(pubkey_buffer: *[public_key_size]u8, privkey_buffer: *[secret_key_size]u8, rng: rngProvider) !void {
+pub fn generateKeys(pubkey_buffer: ?*[public_key_length]u8, privkey_buffer: *[secret_key_length]u8, rng: rngProvider) !void {
     
     var seed_buffer: [Ed25519.KeyPair.seed_length]u8 = undefined;
     rng.generate(&seed_buffer);
     const keypair: Ed25519.KeyPair = Ed25519.KeyPair.generateDeterministic(seed_buffer) catch return CryptoError.FailedKeyGeneration;
     
-    
-    @memcpy(pubkey_buffer[0..public_key_size], &keypair.public_key.bytes);
-    @memcpy(privkey_buffer[0..secret_key_size], &keypair.secret_key.bytes);
+    if (pubkey_buffer != null) @memcpy(pubkey_buffer.?[0..public_key_length], &keypair.public_key.bytes);
+    @memcpy(privkey_buffer[0..secret_key_length], &keypair.secret_key.bytes);
 }
 
-pub fn sign(key: *const [secret_key_size]u8, data: []const u8, signature_out: *const [signature_size]u8) !void {
+pub fn sign(key: *const [secret_key_length]u8, data: []const u8, signature_out: *const [signature_length]u8) !void {
     _ = key;
     _ = data;
     _ = signature_out;
     return CryptoError.NotImplemented;
 }
 
-pub fn verify(key: *const [public_key_size]u8, signature: *const [signature_size]u8, data: []const u8) !void {
+pub fn verify(key: *const [public_key_length]u8, signature: *const [signature_length]u8, data: []const u8) !void {
     // TODO maybe find a more efficient way to do that (excessive copies)
     const sig = Ed25519.Signature.fromBytes(signature.*);
     const pubkey = Ed25519.PublicKey.fromBytes(key.*) catch return CryptoError.InvalidKey;