Which of the following is an example of asymmetric encryption?

PKI relies on asymmetric encryption, in which a public key encrypts data and only the corresponding private key can decrypt it (or vice versa for digital signatures). This public/private key relationship is the defining characteristic of asymmetric cryptography. PKI manages the issuance, distribution, and revocation of digital certificates that bind public keys to identities.

SHA1 is a cryptographic hash function used for data integrity verification, not an encryption algorithm - it produces a one-way digest and does not involve encryption keys.

AES (Advanced Encryption Standard) is a symmetric encryption algorithm that uses a single shared secret key for both encryption and decryption.

3DES (Triple DES) is a symmetric block cipher that applies the DES algorithm three times with one or more secret keys, making it a symmetric rather than asymmetric algorithm.