Password Based Encryption (PBE) is specified in e.g. RFC 2898 which specifies the "PKCS #5: Password-Based Cryptography Specification Version 2.0".
How PBE Works?
A user supplied password which is remembered by the user.
A long with that password text, a random number which is called salt is added and hashed.
Using this a AES or a DES encryption key is derived and encrypted.
The password text is shared between the two parties exchanging the encrypted content in a secure manner.
The receiver, uses the same password and salt and decrypts the content.
PBKDF1 PBKDF1 applies a hash function, which shall be MD2,MD5,SHA-1 to derive keys. The length of the derived key is bounded by the length of the hash function output, which is 16 octets for MD2 and MD5 and 20 octets for SHA-1. PBKDF1 is compatible with the key derivation process in PKCS #5