diff --git a/src/controller.cpp b/src/controller.cpp
index 2d9f723..90e424a 100644
--- a/src/controller.cpp
+++ b/src/controller.cpp
@@ -77,61 +77,49 @@ void Controller::handle_rfid() {
 
 String Controller::read_rfid_data() {
 	log_v("read_rfid_data() running...");
-	static MFRC522::MIFARE_Key keys[8] = {
-		{{0xd3, 0xf7, 0xd3, 0xf7, 0xd3, 0xf7}}, // D3 F7 D3 F7 D3 F7
-		{{0xff, 0xff, 0xff, 0xff, 0xff, 0xff}}, // FF FF FF FF FF FF = factory default
-		{{0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5}}, // A0 A1 A2 A3 A4 A5
-		{{0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5}}, // B0 B1 B2 B3 B4 B5
-		{{0x4d, 0x3a, 0x99, 0xc3, 0x51, 0xdd}}, // 4D 3A 99 C3 51 DD
-		{{0x1a, 0x98, 0x2c, 0x7e, 0x45, 0x9a}}, // 1A 98 2C 7E 45 9A
-		{{0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff}}, // AA BB CC DD EE FF
-		{{0x00, 0x00, 0x00, 0x00, 0x00, 0x00}}  // 00 00 00 00 00 00
-	};
-	log_d("Trying to read RFID data...");
-	
-	String data = "";
+	MFRC522::StatusCode status;
 	MFRC522::PICC_Type type = rfid->PICC_GetType(rfid->uid.sak);
-	
-	uint8_t sectors = 0;
+	uint16_t pageStart = 0;
+	uint16_t pages = 4;
+	uint16_t pageSize = 1;
 	switch(type) {
-		case MFRC522Constants::PICC_TYPE_MIFARE_MINI: sectors = 5; break;
-		case MFRC522Constants::PICC_TYPE_MIFARE_1K: sectors = 16; break;
-		case MFRC522Constants::PICC_TYPE_MIFARE_4K: sectors = 40; break;
-		default: log_i("Unknown PICC type %s\n", String(MFRC522Debug::PICC_GetTypeName(type)).c_str());
-	}
-	sectors = 2; // Pretend we have only two sectors, so we read only sector #1.
-	for (uint8_t sector=1; sector<sectors; sector++) {
-		uint8_t blocks = (sector < 32) ? 4 : 16;
-		uint8_t block_offset = (sector < 32) ? sector * 4 : 128 + (sector - 32) * 16;
-		
-		MFRC522::StatusCode status;
-
-		for (int i=0; i<8; i++) {
-			MFRC522::MIFARE_Key *k = &keys[i];
-			log_v("Trying MIFARE key %02X %02X %02X %02X %02X %02X...\n", k->keyByte[0], k->keyByte[1], k->keyByte[2], k->keyByte[3], k->keyByte[4], k->keyByte[5]);
-			status = rfid->PCD_Authenticate(MFRC522Constants::PICC_CMD_MF_AUTH_KEY_A, block_offset, k, &rfid->uid);
+		case MFRC522Constants::PICC_TYPE_MIFARE_MINI:
+		case MFRC522Constants::PICC_TYPE_MIFARE_1K:
+		case MFRC522Constants::PICC_TYPE_MIFARE_4K: {
+			log_v("Trying to authenticate Mifare card.");
+			MFRC522::MIFARE_Key key = {0xD3, 0xF7, 0xD3, 0xF7, 0xD3, 0xF7};
+			status = rfid->PCD_Authenticate(MFRC522Constants::PICC_CMD_MF_AUTH_KEY_A, 4, &key, &rfid->uid);
 			if (status == MFRC522Constants::STATUS_OK) {
-				log_v("Authentication succeeded with key #%d\n", i);
-				break;
+				log_v("Authentication succeeded.");
+			} else {
+				log_v("Authentication failed. Trying to read anyway.");
 			}
+			pageStart = 4;
+			break;
 		}
-		for (uint8_t block=0; block<blocks-1; block++) {
-			byte buffer[18];
-			uint8_t byte_count = 18;
-			status = rfid->MIFARE_Read(block_offset + block, buffer, &byte_count);
-			if (status != MFRC522Constants::STATUS_OK) {
-				log_d("MIFARE_Read() failed: %s\n", String(MFRC522Debug::GetStatusCodeName(status)).c_str());
-				continue;
-			}
-			for (int i=0; i<16; i++) {
-				if (buffer[i]>=0x20 && buffer[i]<0x7F) data.concat((char)buffer[i]);
-			}
+		case MFRC522Constants::PICC_TYPE_MIFARE_UL:
+			log_v("PICC type is Mifare Ultralight. No authentication necessary.");
+			pages = 16;
+			pageSize = 4;
+			break;
+		default:
+			log_v("Unexpected rfid card type %s. Trying to read anyway.", MFRC522Debug::PICC_GetTypeName(type));
+	}
+	String data = "";
+	for (uint8_t block=pageStart; block<pages+pageStart; block+=pageSize) {
+		byte buffer[18];
+		uint8_t byte_count = 18;
+		status = rfid->MIFARE_Read(block, buffer, &byte_count);
+		if (status != MFRC522Constants::STATUS_OK) {
+			log_d("MIFARE_Read() failed: %s\n", String(MFRC522Debug::GetStatusCodeName(status)).c_str());
+			continue;
+		}
+		for (int i=0; i<16; i++) {
+			if (buffer[i]>=0x20 && buffer[i]<0x7F) data.concat((char)buffer[i]);
 		}
 	}
-	
-	//_rfid->PICC_HaltA();
 	rfid->PCD_StopCrypto1();
-	log_d("Data from RFID: %s\n", data.c_str());
+	log_v("Read rfid data: '%s'", data.c_str());
 	return data;
 }