<PackageReference Include="BouncyCastle.Cryptography" Version="2.6.1" />

IAsymmetricBlockCipher

public interface IAsymmetricBlockCipher
namespace Org.BouncyCastle.Crypto { public interface IAsymmetricBlockCipher { string AlgorithmName { get; } void Init(bool forEncryption, ICipherParameters parameters); int GetInputBlockSize(); int GetOutputBlockSize(); byte[] ProcessBlock(byte[] inBuf, int inOff, int inLen); } }