diff --git a/src/arcfour.h b/src/arcfour.h
index 842a72a..0c2dbbb 100644
--- a/src/arcfour.h
+++ b/src/arcfour.h
@@ -30,15 +30,13 @@ class arcfour : public streamcipher
 	inttype I, J;
 	inttype mask;
 public:
-	bool init () {
+	void init () {
 		size_t Ssize = 1 << bits;
-		if (bits > 8 * sizeof (inttype) ) return false;
 		I = J = 0;
 		S.resize (Ssize);
 		mask = ~ (inttype) 0;
 		if ( (inttype) (1 << bits) ) mask %= 1 << bits;
 		for (size_t i = 0; i < Ssize; ++i) S[i] = i;
-		return true;
 	}
 
 	void clear() {
@@ -97,6 +95,10 @@ public:
 		gen (n, & (out[0]) );
 	}
 
+	size_t key_size() {
+		return 256;
+	}
+
 	size_t block_size() {
 		return 1;
 	}
diff --git a/src/hashfile.cpp b/src/hashfile.cpp
index 42a816b..55ba6fd 100644
--- a/src/hashfile.cpp
+++ b/src/hashfile.cpp
@@ -60,7 +60,7 @@ class size64proc : public hash_proc
 };
 
 /*
- * list of hash functions availabel
+ * list of hash functions available
  */
 
 typedef map<string, hash_proc*> hashmap;
diff --git a/src/sc.h b/src/sc.h
index e64259f..f760558 100644
--- a/src/sc.h
+++ b/src/sc.h
@@ -26,11 +26,14 @@
 class streamcipher
 {
 public:
-	virtual bool init() = 0;
+	virtual void init() = 0;
 	virtual void clear() = 0;
 	virtual void load_key (const byte*begin, const byte*end) = 0;
 	virtual byte gen() = 0;
 	virtual void gen (size_t n, byte*out) = 0;
+
+	//advisory values for effective usage
+	virtual size_t key_size() = 0;
 	virtual size_t block_size() = 0;
 
 	void discard (size_t n) {