algos_sig: added H=20 fmtseq variant

...that provide around 1 million signatures per key. That seems more
than sufficient for human usage.

Note that generating the key takes 16 times longer than for already
present algorithms (that have H=16). On my computer, it is around 4
minutes for fmtseq128N20 and 16 minutes for fmtseq256N20.

src/algo_suite.cpp

@@ -23,21 +23,15 @@
 
 void fill_algorithm_suite (algorithm_suite&s)
 {
-	static algo_mceqd128 mce128;
-	mce128.register_into_suite (s);
-
-	static algo_mceqd192 mce192;
-	mce192.register_into_suite (s);
-
-	static algo_mceqd256 mce256;
-	mce256.register_into_suite (s);
-
-	static algo_fmtseq128 fmt128;
-	fmt128.register_into_suite (s);
-
-	static algo_fmtseq192 fmt192;
-	fmt192.register_into_suite (s);
-
-	static algo_fmtseq256 fmt256;
-	fmt256.register_into_suite (s);
+#define do_alg(x) static x var_##x ; var_##x.register_into_suite(s);
+	do_alg (algo_mceqd128);
+	do_alg (algo_mceqd192);
+	do_alg (algo_mceqd256);
+	do_alg (algo_fmtseq128);
+	do_alg (algo_fmtseq192);
+	do_alg (algo_fmtseq256);
+	do_alg (algo_fmtseq128h20);
+	do_alg (algo_fmtseq192h20);
+	do_alg (algo_fmtseq256h20);
+#undef do_alg
 }

src/algos_sig.cpp

@@ -270,3 +270,115 @@ int algo_fmtseq256::create_keypair (sencode**pub, sencode**priv, prng&rng)
 	return 0;
 }
 
+/*
+ * h=20 variants for signature count 1048576.
+ *
+ * Chosen were parameters h=4,l=5 over the h=5,l=4 variant for smaller runtime
+ * space needed, as signature time is not really a concern here.
+ */
+
+int algo_fmtseq128h20::sign (const bvector&msg,
+                             bvector&sig,
+                             sencode**privkey,
+                             bool&dirty,
+                             prng&rng)
+{
+	return fmtseq_generic_sign
+	       <4, 5, 256, sha256hash, rmd128hash>
+	       (msg, sig, privkey, dirty, rng);
+}
+
+int algo_fmtseq128h20::verify (const bvector&sig,
+                               const bvector&msg,
+                               sencode*pubkey)
+{
+	return fmtseq_generic_verify
+	       <4, 5, 256, sha256hash, rmd128hash>
+	       (sig, msg, pubkey);
+}
+
+int algo_fmtseq192h20::sign (const bvector&msg,
+                             bvector&sig,
+                             sencode**privkey,
+                             bool&dirty,
+                             prng&rng)
+{
+	return fmtseq_generic_sign
+	       <4, 5, 384, sha384hash, tiger192hash>
+	       (msg, sig, privkey, dirty, rng);
+}
+
+int algo_fmtseq192h20::verify (const bvector&sig,
+                               const bvector&msg,
+                               sencode*pubkey)
+{
+	return fmtseq_generic_verify
+	       <4, 5, 384, sha384hash, tiger192hash>
+	       (sig, msg, pubkey);
+}
+
+int algo_fmtseq256h20::sign (const bvector&msg,
+                             bvector&sig,
+                             sencode**privkey,
+                             bool&dirty,
+                             prng&rng)
+{
+	return fmtseq_generic_sign
+	       <4, 5, 512, sha512hash, sha256hash>
+	       (msg, sig, privkey, dirty, rng);
+}
+
+int algo_fmtseq256h20::verify (const bvector&sig,
+                               const bvector&msg,
+                               sencode*pubkey)
+{
+	return fmtseq_generic_verify
+	       <4, 5, 512, sha512hash, sha256hash>
+	       (sig, msg, pubkey);
+}
+
+int algo_fmtseq128h20::create_keypair (sencode**pub, sencode**priv, prng&rng)
+{
+	fmtseq::pubkey Pub;
+	fmtseq::privkey Priv;
+
+	rmd128hash hf;
+
+	if (fmtseq::generate (Pub, Priv, rng, hf, 256, 4, 5) )
+		return 1;
+
+	*pub = Pub.serialize();
+	*priv = Priv.serialize();
+	return 0;
+}
+
+int algo_fmtseq192h20::create_keypair (sencode**pub, sencode**priv, prng&rng)
+{
+	fmtseq::pubkey Pub;
+	fmtseq::privkey Priv;
+
+	tiger192hash hf;
+
+	if (fmtseq::generate (Pub, Priv, rng, hf, 384, 4, 5) )
+		return 1;
+
+	*pub = Pub.serialize();
+	*priv = Priv.serialize();
+	return 0;
+}
+
+int algo_fmtseq256h20::create_keypair (sencode**pub, sencode**priv, prng&rng)
+{
+	fmtseq::pubkey Pub;
+	fmtseq::privkey Priv;
+
+	sha256hash hf;
+
+	if (fmtseq::generate (Pub, Priv, rng, hf, 512, 4, 5) )
+		return 1;
+
+	*pub = Pub.serialize();
+	*priv = Priv.serialize();
+	return 0;
+}
+

src/algos_sig.h

@@ -87,5 +87,71 @@ public:
 	int create_keypair (sencode**pub, sencode**priv, prng&rng);
 };
 
+class algo_fmtseq128h20 : public algorithm
+{
+public:
+	bool provides_signatures() {
+		return true;
+	}
+
+	bool provides_encryption() {
+		return false;
+	}
+
+	std::string get_alg_id() {
+		return "FMTSEQ128H20-SHA256-RIPEMD128";
+	}
+
+	virtual int sign (const bvector&msg, bvector&sig,
+	                  sencode** privkey, bool&dirty, prng&rng);
+	virtual int verify (const bvector&sig, const bvector&msg,
+	                    sencode* pubkey);
+	int create_keypair (sencode**pub, sencode**priv, prng&rng);
+};
+
+class algo_fmtseq192h20 : public algorithm
+{
+public:
+	bool provides_signatures() {
+		return true;
+	}
+
+	bool provides_encryption() {
+		return false;
+	}
+
+	std::string get_alg_id() {
+		return "FMTSEQ192H20-SHA384-TIGER192";
+	}
+
+	virtual int sign (const bvector&msg, bvector&sig,
+	                  sencode** privkey, bool&dirty, prng&rng);
+	virtual int verify (const bvector&sig, const bvector&msg,
+	                    sencode* pubkey);
+	int create_keypair (sencode**pub, sencode**priv, prng&rng);
+};
+
+class algo_fmtseq256h20 : public algorithm
+{
+public:
+	bool provides_signatures() {
+		return true;
+	}
+
+	bool provides_encryption() {
+		return false;
+	}
+
+	std::string get_alg_id() {
+		return "FMTSEQ256H20-SHA512-SHA256";
+	}
+
+	virtual int sign (const bvector&msg, bvector&sig,
+	                  sencode** privkey, bool&dirty, prng&rng);
+	virtual int verify (const bvector&sig, const bvector&msg,
+	                    sencode* pubkey);
+	int create_keypair (sencode**pub, sencode**priv, prng&rng);
+};
+
 #endif