A producer system may insert an encrypted value in a field in a message, where the message is associated with a schema that specifies a public key used to encrypt the encrypted value of the field and further specifies a type of an unencrypted form of the encrypted value, insert one or more unencrypted values in one or more fields in the message, and send the message to an external computing system. A consumer system may receive the message, determine, based at least in part on the public key specified by the schema, a private key associated with the public key, and decrypt, using the private key, the encrypted value of the field into the unencrypted form of the encrypted value.