belt and suspenders
expressionops culturesecurity
Wearing two independent safeguards for the same failure - if one lets go, the trousers stay up.
The idiom for deliberate redundancy of controls: backup and replication, MFA and conditional access, dual power feeds. The word 'independent' carries the weight; two straps anchored to the same failing point are one strap with extra steps.
Also known as: belt and braces