The 128 bit strong key is applicable for symmetric key encryption (e.g. AES, Blowfish etc.). However, even 2048 bit keys are considered relatively insecure for

The 128 bit strong key is applicable for symmetric key encryption (e.g. AES, Blowfish etc.). However, even 2048 bit keys are considered relatively insecure for asymmetric key encryption (e.g. RSA).