Question 1

What is AES?

Accepted Answer

AES (Advanced Encryption Standard) is a symmetric block cipher standardized by NIST in 2001. It encrypts 128-bit blocks with key sizes of 128, 192 or 256 bits. AES-256 is widely used in TLS, disk encryption, file archiving and password managers.

Question 2

Is AES encryption secure?

Accepted Answer

Yes. AES is considered cryptographically secure and is approved by the U.S. government for top-secret information. No practical attack breaks AES when used with a strong random key and a proper mode such as CBC or GCM.

Question 3

What's the difference between AES-128, AES-192 and AES-256?

Accepted Answer

The number is the key size in bits. AES-128 has 10 rounds, AES-192 has 12 rounds and AES-256 has 14 rounds. All three are considered secure; AES-256 just gives the largest keyspace. Slower hardware benefits most from AES-128.

Question 4

Do I need to use an IV?

Accepted Answer

For CBC, CFB and OFB modes, yes — a unique random IV of exactly 16 bytes must be used for every encryption. The tool generates a fresh random IV each time. For ECB mode no IV is needed but the mode is generally insecure for variable-length data.