The attached document attached contains an example of how to encrypt and decrypt data in a Greenplum Database (GPDB) database with the GPDB pgcrypto extension package and the gpg encryption utility.
The GPDB extension package pgcrypto provides built-in cryptographic functions (for data at rest) to encrypt and decrypt sensitive information, such as SSNs, credit card numbers, etc. pgcrypto provides PGP encryption functions using symmetric and asymmetric encryption.
The gpg utility is used to create PGP public and private keys that are used to encrypt and decrypt the data stored in the GPDB database.
This document does not cover all encryption features available the with the pgcrypto extension package. Please refer to the GPDB documentation guides for information on how to use and implement specific features.