unbreachable
Cannot be breached
Unbreachable means impossible to breach or break through.
An unbreachable wall cannot be penetrated; an unbreachable contract has no loopholes.
The word applies to physical barriers, security systems, or abstract defenses: The fortress proved unbreachable, unbreachable encryption.
Often used for emphasis where *impenetrable* or *airtight* might serve equally well.
Fortified urban stronghold
- strongholdFortified place of defense
- bastionFortified defensive position
- rampartFortified defensive wall
- bulwarkDefensive fortification or safeguard
fortress · battlements · palisade · curtain wall · barbican · gatehouse · moat · drawbridge
Impossible to damage permanently
- invulnerableImmune to all harm
- imperviousUnable to be affected
- unassailableImpossible to attack successfully
- unconquerableImpossible to defeat
insurmountable · indomitable · unyielding · adamantine · bulletproof · armored · ironclad · untouchable
Transformed into cipher
- firewallNetwork access control system
- tamper-proofResistant to unauthorized modification
- authenticationConfirming genuine identity
- cybersecurityProtection of digital systems
vault · lockdown · shielded · safeguarded · confidential · surveillance · airtight · watertight
citadel
Fortified urban stronghold
- strongholdFortified place of defense
- bastionFortified defensive position
- rampartFortified defensive wall
bulwark · fortress · battlements · palisade · curtain wall · barbican · gatehouse · moat · drawbridge · keep
indestructible
Impossible to damage permanently
- invulnerableImmune to all harm
- imperviousUnable to be affected
- unassailableImpossible to attack successfully
unconquerable · insurmountable · indomitable · unyielding · adamantine · bulletproof · armored · ironclad · untouchable · inexorable
encrypted
Transformed into cipher
- firewallNetwork access control system
- tamper-proofResistant to unauthorized modification
- authenticationConfirming genuine identity
cybersecurity · vault · lockdown · shielded · safeguarded · confidential · surveillance · airtight · watertight · hermetic
unbreachablebreachable
Capable of being penetrated
penetrable · vulnerable · permeable · assailable · accessible
breach, unbreakable, breachable, impenetrable, breached, impregnable, breaches, breaching, impenetrability