JAVA RSA Generate KeyPair, Encryption, Decryption and Performance Testing

Motivation

To try RSA Enc/Dec and check its performance.

Simple Note

Test file TestRSAUtils.java

Implementation RSAUtils.java

Performance testing TestRSAPerformance.java

Refactoring

Move AESUtils.encrypt and AESUtils.decrypt to CryptoUtils since they are no different from RSA encrypt/decrypt.

Still wrap them in AESUtils/RSAUtils for convenience.
(Can import less class) (Just one class less)

Hmm...


Performance Testing

Test over
PublicKey/PrivateKey, Encryption/Decryption,
Create Cipher each time/Reuse Cipher,
Key Size 1024/2048/4096/8192 bits
total 32 cases, 100 runs each

Results listed in the google sheet
JAVA RSA Performance Testing

Not very accurate but...

Summary

1. PublicKey Enc/Dec is faster than PrivateKey Enc/Dec

2. Key Size affects, the longer the slower.

3. Reuse Cipher similar to create Cipher each time, sometimes even slower.

Conclusions

1. Use proper Key Size, 2048 probably a good choice.

2. Can create Cipher each time, no need to cache it.

3. Can also cache and reuse Cipher, will slightly increase performance in most cases.

References

Java: How can I generate PrivateKey from a string?

Load RSA public key from file

JAVA AES Encryption Decryption with IV, Salt and any length of Key

Simple Note

See the method TestEncryptDecryptWithKeyIvSalt in TestAESUtils.java

and getCipher(int mode, char[] key, byte[] ivBytes, byte[] saltBytes) in AESUtils.java

References

Java 256-bit AES Password-Based Encryption


Java AES and using my own Key

Java AES Key Generation, Encryption and Decryption

Simple Note

Test File:
  TestAESUtils.java

Utils Implementation
  AESUtils.java
  CryptoUtils.java

If you get Illegal key size error, probably need to download JCE Jars, please refer to

InvalidKeyException Illegal key size

and

Java Security: Illegal key size or default parameters?


Other References

The article teach me use char[] over String
Why is char[] preferred over String for passwords?

This one teach me basic Encryption and Decryption
Initial bytes incorrect after Java AES/CBC decryption

How to convert between char[] and byte[]
Converting char[] to byte[]