RSA encryption slow decoding

[1AlexFix1]

Hello, on the physical device(iOS), on Android it fast, wild slow work with rsa, decryption with a private key on average 6 seconds, generation of keys with such parameters RSAKeyGeneratorParameters (BigInt.from (65537), 2048, 12); Flutter: start time 42:48 Flutter: time is the end 46:10 which is very long. At the moment there is no possibility to collect the release version, so the question with the release version somehow helps or the problem lies deeper?

Tuple2<RSAPublicKey, RSAPrivateKey> generateKeyPair() {
    var random = Random.secure();
    var key = Uint8List.fromList(List.generate(32, (_) => random.nextInt(255)));
    var secureRandom = FortunaRandom()..seed(KeyParameter(key));
    var rsaParams = RSAKeyGeneratorParameters(BigInt.from(65537), 2048, 12);
    var keyGenerator = RSAKeyGenerator()
      ..init(ParametersWithRandom(rsaParams, secureRandom));
    AsymmetricKeyPair keys = keyGenerator.generateKeyPair();
    return Tuple2(keys.publicKey, keys.privateKey);
  }

[Vanethos]

In my experience, the release version boosted the speed of creating the keys.

Also, using https://api.dartlang.org/stable/2.1.0/dart-isolate/dart-isolate-library.html helped me boosting performance

[1AlexFix1]

In release build RSA encryption fast