Java Security

Hi, I'm trying to implement a method to synchronize TOTP cards. In case the server clock and the card clock were different. So I generate a lot of TOTP keys in case to compare it with the real key so at the end I get both of the times in the server. That works in x86 (Sunfire x2200) perfectly and does not take a lot of time doing that (like 2 minutes generating 800000 keys). But when I test it on Oracle BM SPARC (T1000 LDOM 1.1) takes I lot of time. I did all kind of profiling stuff but all point to the method of the generation the TOTP in the HMAC_SHA1.

here is the code (based on JBoss 6 OTP implementation)

public synchronized static String generateTOTP(String key, String time,  int returnDigits, String crypto) throws GeneralSecurityException { 
		String result = null;
		byte[] hash;
		// Using the counter
		// First 8 bytes are for the movingFactor
		// Complaint with base RFC 4226 (HOTP)
		while(time.length() < 16 ) {
			time = "0" + time;
		}
		// Get the HEX in a Byte[]
		byte[] msg = hexStr2Bytes(time);
		// Adding one byte to get the right conversion
		byte[] k = hexStr2Bytes(key);
		hash = hmac_sha1(crypto, k, msg);
		// put selected bytes into result int
		int offset = hash[hash.length - 1] & 0xf;
		int binary =
			((hash[offset] & 0x7f) << 24) |
			((hash[offset + 1] & 0xff) << 16) |
			((hash[offset + 2] & 0xff) << 8) |
			(hash[offset + 3] & 0xff);
		int otp = binary % DIGITS_POWER[ returnDigits ];
		result = Integer.toString(otp);
		while (result.length() < returnDigits ) {
			result = "0" + result;
		}
		return result;
}

private static byte[] hmac_sha1(String crypto, byte[] keyBytes, byte[] text) throws GeneralSecurityException {
		Mac hmac;
		hmac = Mac.getInstance(crypto);
		SecretKeySpec macKey = new SecretKeySpec(keyBytes, "RAW");
		hmac.init(macKey);
		return hmac.doFinal(text);
}

The release of the version to production is delayed about this. I need help either to use another library or finding the right configuration for the SPARC.

Thanks in advance to everybody.

danielfjb