Which encryption standard uses three passes of encryption?

The encryption standard that uses three passes of encryption is 3DES, or Triple Data Encryption Standard. This algorithm enhances the original DES (Data Encryption Standard) by applying the encryption process three times to each data block. 3DES is designed to provide a much higher level of security than its predecessor, which was increasingly vulnerable due to advances in computing power that made it feasible to brute-force DES-encrypted messages.

In practice, 3DES works by first encrypting the plaintext with a first key, then decrypting it with a second key, and finally encrypting it again with a third key. This triple-layered encryption significantly increases the effective key length, making it much more difficult for unauthorized parties to decrypt the data without the correct keys.

The other options provided do not match the criteria as closely. AES (Advanced Encryption Standard) uses a different structure and can operate with key lengths of 128, 192, or 256 bits but does not inherently involve three passes in its encryption mode. SHA-256 is not an encryption standard; rather, it is a hashing algorithm that produces a fixed-size output (256 bits) from input data, focusing on data integrity rather than confidentiality. RSA is an asymmetric encryption algorithm that relies on a pair of