"Rman Backup Error du to "ORA-12269: client uses weak encryption/crypto-checksumming version

When Taking backup for Oracle data base I keep getting the below error:

RMAN-00571: ======================================================
RMAN-00569: ============ ERROR MASSAGE STACK FOLLOWS =============
RMAN-00571: ======================================================
RMAN - 12001: Could not open channel ch02
RMAN-10008: Could not create channel context
RMAN: unable to connect to target database
ORA-12269: client uses weak encryption/crypto-checksumming version