diff --git a/src/dht/announcereq.h b/src/dht/announcereq.h
--- a/src/dht/announcereq.h
+++ b/src/dht/announcereq.h
@@ -34,21 +34,21 @@
 	{
 	public:
 		AnnounceReq();
-		AnnounceReq(const Key & id,const Key & info_hash,bt::Uint16 port,const Key & token);
+		AnnounceReq(const Key & id,const Key & info_hash,bt::Uint16 port,const QByteArray & token);
 		~AnnounceReq() override;
 		
 		void apply(DHT* dh_table) override;
 		void print() override;
 		void encode(QByteArray & arr) const override;
 		void parse(bt::BDictNode* dict) override;
 		
-		const Key & getToken() const {return token;}
+		const QByteArray & getToken() const {return token;}
 		bt::Uint16 getPort() const {return port;}
 		
 		typedef QSharedPointer<AnnounceReq> Ptr;
 	private:
 		bt::Uint16 port;
-		Key token;
+		QByteArray token;
 	};
 
 }
diff --git a/src/dht/announcereq.cpp b/src/dht/announcereq.cpp
--- a/src/dht/announcereq.cpp
+++ b/src/dht/announcereq.cpp
@@ -35,7 +35,7 @@
 		method = dht::ANNOUNCE_PEER;
 	}
 
-	AnnounceReq::AnnounceReq(const Key & id, const Key & info_hash, Uint16 port, const Key & token)
+	AnnounceReq::AnnounceReq(const Key & id, const Key & info_hash, Uint16 port, const QByteArray & token)
 			: GetPeersReq(id, info_hash), port(port), token(token)
 	{
 		method = dht::ANNOUNCE_PEER;
@@ -48,11 +48,33 @@
 		dh_table->announce(*this);
 	}
 
+	QString tokenToHex(const QByteArray &token)
+	{
+		// slightly modified implementation of QByteArray::ToHex() (since Qt 5.9)
+		// copied here to keep minimal Qt ver. requirement eq. to 5.7
+		QByteArray hex(token.size() * 2, Qt::Uninitialized);
+		char *hexData = hex.data();
+		const uchar *data = (const uchar *)token.data();
+		for (int i = 0; i < token.size(); ++i) {
+			int j = (data[i] >> 4) & 0xf;
+			if (j <= 9)
+				hexData[i*2] = (j + '0');
+			 else
+				hexData[i*2] = (j + 'A' - 10); // <- use upper case
+			j = data[i] & 0xf;
+			if (j <= 9)
+				hexData[i*2+1] = (j + '0');
+			 else
+				hexData[i*2+1] = (j + 'A' - 10);
+		}
+		return QString(hex);
+	}
+
 	void AnnounceReq::print()
 	{
 		Out(SYS_DHT | LOG_DEBUG) << QString("REQ: %1 %2 : announce_peer %3 %4 %5")
 		.arg(mtid[0]).arg(id.toString()).arg(info_hash.toString())
-		.arg(port).arg(token.toString()) << endl;
+		.arg(port).arg(tokenToHex(token)) << endl;
 	}
 
 	void AnnounceReq::encode(QByteArray & arr) const
@@ -65,7 +87,8 @@
 				enc.write(QByteArrayLiteral("id")); enc.write(id.getData(), 20);
 				enc.write(QByteArrayLiteral("info_hash")); enc.write(info_hash.getData(), 20);
 				enc.write(QByteArrayLiteral("port")); enc.write((Uint32)port);
-				enc.write(QByteArrayLiteral("token")); enc.write(token.getData(), 20);
+				// must cast data() to (const Uint8*) to call right write() overload
+				enc.write(QByteArrayLiteral("token")); enc.write((const Uint8*)token.data(), token.size());
 			}
 			enc.end();
 			enc.write(REQ); enc.write(QByteArrayLiteral("announce_peer"));
@@ -84,7 +107,7 @@
 		
 		info_hash = Key(args->getByteArray("info_hash"));
 		port = args->getInt("port");
-		token = Key(args->getByteArray("token"));
+		token = args->getByteArray("token").left(MAX_TOKEN_SIZE);
 	}
 }
 
diff --git a/src/dht/announcetask.h b/src/dht/announcetask.h
--- a/src/dht/announcetask.h
+++ b/src/dht/announcetask.h
@@ -30,14 +30,14 @@
 
 	class KBucketEntryAndToken : public KBucketEntry
 	{
-		Key token;
+		QByteArray token;
 	public:
 		KBucketEntryAndToken() {}
-		KBucketEntryAndToken(const KBucketEntry & e, const Key & token)
+		KBucketEntryAndToken(const KBucketEntry & e, const QByteArray & token)
 				: KBucketEntry(e), token(token) {}
 		~KBucketEntryAndToken() override {}
 
-		const Key & getToken() const
+		const QByteArray & getToken() const
 		{
 			return token;
 		}
diff --git a/src/dht/database.h b/src/dht/database.h
--- a/src/dht/database.h
+++ b/src/dht/database.h
@@ -112,17 +112,17 @@
 		 * Generate a write token, which will give peers write access to
 		 * the DB.
 		 * @param addr The address of the peer
-		 * @return A Key
+		 * @return A QByteArray
 		 */
-		dht::Key genToken(const net::Address & addr);
+		QByteArray genToken(const net::Address & addr);
 
 		/**
 		 * Check if a received token is OK.
 		 * @param token The token received
 		 * @param addr The address of the peer
 		 * @return true if the token was given to this peer, false other wise
 		 */
-		bool checkToken(const dht::Key & token, const net::Address & addr);
+		bool checkToken(const QByteArray & token, const net::Address & addr);
 
 		/// Test whether or not the DB contains a key
 		bool contains(const dht::Key & key) const;
@@ -132,7 +132,7 @@
 		
 	private:
 		bt::PtrMap<dht::Key, DBItemList> items;
-		QMap<dht::Key, bt::TimeStamp> tokens;
+		QMap<QByteArray, bt::TimeStamp> tokens;
 	};
 
 }
diff --git a/src/dht/database.cpp b/src/dht/database.cpp
--- a/src/dht/database.cpp
+++ b/src/dht/database.cpp
@@ -127,7 +127,7 @@
 		}
 	}
 
-	dht::Key Database::genToken(const net::Address & addr)
+	QByteArray Database::genToken(const net::Address & addr)
 	{
 		if (addr.ipVersion() == 4)
 		{
@@ -139,7 +139,7 @@
 			bt::WriteUint16(tdata, 4, addr.port());
 			bt::WriteUint64(tdata, 6, now);
 
-			dht::Key token = SHA1Hash::generate(tdata, 14);
+			QByteArray token = SHA1Hash::generate(tdata, 14).toByteArray();
 			// keep track of the token, tokens will expire after a while
 			tokens.insert(token, now);
 			return token;
@@ -154,14 +154,14 @@
 			bt::WriteUint16(tdata, 16, addr.port());
 			bt::WriteUint64(tdata, 18, now);
 
-			dht::Key token = SHA1Hash::generate(tdata, 26);
+			QByteArray token = SHA1Hash::generate(tdata, 26).toByteArray();
 			// keep track of the token, tokens will expire after a while
 			tokens.insert(token, now);
 			return token;
 		}
 	}
 
-	bool Database::checkToken(const dht::Key & token, const net::Address & addr)
+	bool Database::checkToken(const QByteArray & token, const net::Address & addr)
 	{
 		// the token must be in the map
 		if (!tokens.contains(token))
@@ -177,7 +177,7 @@
 			bt::WriteUint32(tdata, 0, addr.toIPv4Address());
 			bt::WriteUint16(tdata, 4, addr.port());
 			bt::WriteUint64(tdata, 6, ts);
-			dht::Key ct = SHA1Hash::generate(tdata, 14);
+			QByteArray ct = SHA1Hash::generate(tdata, 14).toByteArray();
 
 			// compare the generated token to the one received
 			if (token != ct)  // not good, this peer didn't went through the proper channels
@@ -194,7 +194,7 @@
 			bt::WriteUint16(tdata, 16, addr.port());
 			bt::WriteUint64(tdata, 18, ts);
 
-			dht::Key ct = SHA1Hash::generate(tdata, 26);
+			QByteArray ct = SHA1Hash::generate(tdata, 26).toByteArray();
 			// compare the generated token to the one received
 			if (token != ct)  // not good, this peer didn't went through the proper channels
 			{
diff --git a/src/dht/dht.cpp b/src/dht/dht.cpp
--- a/src/dht/dht.cpp
+++ b/src/dht/dht.cpp
@@ -187,7 +187,7 @@
 
 		node->received(this, r);
 		// first check if the token is OK
-		dht::Key token = r.getToken();
+		QByteArray token = r.getToken();
 		if (!db->checkToken(token, r.getOrigin()))
 			return;
 
@@ -215,7 +215,7 @@
 		db->sample(r.getInfoHash(), dbl, 50, r.getOrigin().ipVersion());
 
 		// generate a token
-		dht::Key token = db->genToken(r.getOrigin());
+		QByteArray token = db->genToken(r.getOrigin());
 
 		bt::Uint32 wants = 0;
 		if (r.wants(4) || r.getOrigin().ipVersion() == 4)
diff --git a/src/dht/getpeersrsp.h b/src/dht/getpeersrsp.h
--- a/src/dht/getpeersrsp.h
+++ b/src/dht/getpeersrsp.h
@@ -35,23 +35,23 @@
 	{
 	public:
 		GetPeersRsp();
-		GetPeersRsp(const QByteArray & mtid, const Key & id, const Key & token);
-		GetPeersRsp(const QByteArray & mtid, const Key & id, const DBItemList & values, const Key & token);
+		GetPeersRsp(const QByteArray & mtid, const Key & id, const QByteArray & token);
+		GetPeersRsp(const QByteArray & mtid, const Key & id, const DBItemList & values, const QByteArray & token);
 		~GetPeersRsp() override;
 
 		void apply(DHT* dh_table) override;
 		void print() override;
 		void encode(QByteArray & arr) const override;
 		void parse(bt::BDictNode* dict) override;
 
 		const DBItemList & getItemList() const {return items;}
-		const Key & getToken() const {return token;}
+		const QByteArray & getToken() const {return token;}
 		bool containsNodes() const {return nodes.size() > 0 || nodes6.size() > 0;}
 		bool containsValues() const {return nodes.size() == 0;}
 
 		typedef QSharedPointer<GetPeersRsp> Ptr;
 	private:
-		Key token;
+		QByteArray token;
 		DBItemList items;
 	};
 
diff --git a/src/dht/getpeersrsp.cpp b/src/dht/getpeersrsp.cpp
--- a/src/dht/getpeersrsp.cpp
+++ b/src/dht/getpeersrsp.cpp
@@ -32,17 +32,17 @@
 namespace dht
 {
 	GetPeersRsp::GetPeersRsp()
-			: RPCMsg(QByteArray(), dht::GET_PEERS, dht::RSP_MSG, Key())
+			: RPCMsg(QByteArray(), dht::GET_PEERS, dht::RSP_MSG, QByteArray())
 	{
 	}
 
-	GetPeersRsp::GetPeersRsp(const QByteArray & mtid, const Key & id, const Key & token)
+	GetPeersRsp::GetPeersRsp(const QByteArray & mtid, const Key & id, const QByteArray & token)
 			: RPCMsg(mtid, dht::GET_PEERS, dht::RSP_MSG, id), 
 			token(token)
 	{
 	}
 
-	GetPeersRsp::GetPeersRsp(const QByteArray & mtid, const Key & id, const DBItemList & values, const Key & token)
+	GetPeersRsp::GetPeersRsp(const QByteArray & mtid, const Key & id, const DBItemList & values, const QByteArray & token)
 			: RPCMsg(mtid, dht::GET_PEERS, dht::RSP_MSG, id), 
 			token(token), 
 			items(values)
@@ -82,8 +82,9 @@
 					enc.write(QByteArrayLiteral("nodes6")); 
 					enc.write(nodes6);
 				}
-				
-				enc.write(QByteArrayLiteral("token")); enc.write(token.getData(), 20);
+
+				// must cast data() to (const Uint8*) to call right write() overload
+				enc.write(QByteArrayLiteral("token")); enc.write((const Uint8*)token.data(), token.size());
 				
 				if (items.size() > 0)
 				{
@@ -114,7 +115,7 @@
 		if (!args)
 			throw bt::Error("Invalid response, arguments missing");
 
-		token = Key(args->getByteArray("token"));
+		token = args->getByteArray("token").left(MAX_TOKEN_SIZE);
 
 		BListNode* vals = args->getList("values");
 		if (vals)
diff --git a/src/dht/rpcmsg.h b/src/dht/rpcmsg.h
--- a/src/dht/rpcmsg.h
+++ b/src/dht/rpcmsg.h
@@ -34,6 +34,9 @@
 
 namespace dht
 {
+
+#define MAX_TOKEN_SIZE 40
+
 	class DHT;
 
 	enum Type