Secure and efficient cryptography library for Android. (Auto fix SecureRandom bugs in API 18 and below.)

Features:
- AES-256 encryption algorithm
- CBC/CTR mode of operations
- Block padding with PKCS7 (only with CBC)
- Computationally secure random salt (of cipher block size)
- Password stretching with PBKDF2
- Random IV generated on each encryption (16 bytes)
- Supports MD5 SHA1 and SHA2 hash functions
- Generate secure keys with SecureRandom or random.org
- Asymmetric encryption with RSA
- Auto handle large data by using hybrid asymmetric encryption
- Asymmetric RSA signing and verification
- Supported RSA key sizes are 2048 bits and 4096 bits
- Password analysis for strength crack times weakness etc using nulab's zxcvbn4j library