Access control can cover a wide variety of devices used to secure structures, grounds and containers. Access control solutions can include security officers, locks and keys, electronic combination locks, access cards, key fobs and readers, license plate recognition systems, biometric systems and radio frequency devices.
Here are some of the advantages and disadvantages of a few basic mechanical and electronic access control systems. The ability of these systems to discriminate between authorized and unauthorized access varies.
Locks and Keys
Locks and keys are the most common method used to controlling access. Key blanks can be generic or proprietary. Generic keys can be duplicated at any local lock shop, while proprietary keys require a special blank that is unique to an institution or district.
Advantages:
- Simple and inexpensive initial cost
Disadvantages:
- Key loss may require expensive rekeying of all affected locks
- Many keys are easily duplicated and distributed without authorization
- Key systems are vulnerable to lock picking
- Key control systems can be costly and time consuming
Application:
Key and lock systems are best used for low security applications. Institutional key systems should be limited to proprietary key systems with strong key control policy and inventory records of all keys and proprietary blanks.
Combination Locks
Combination locks can be either mechanical or electronic. The electronic combination locks have the advantage of allowing special features such as reprogrammable combinations, multiple combinations for individual users, time delay opening and entry alert features.
Advantages:
- Simple and easy to install, though more expensive than key and lock systems
- Can be individual or part of a network
- No added cost for keys, fobs or cards
Disadvantages:
- Staff will share their combinations with unauthorized users out of convenience
- Combinations are compromised by watching an authorized person enter their code
- Combinations are easy to forget
- System maintenance and record keeping can be costly
Application: Not recommended – limit to low security applications and ID verification
Electronic Card and Key Fob Access
Electronic cards and key fobs have the advantage of identifying the authorized user to the access reader, although, they cannot prevent the authorized user from loaning their card to an unauthorized person. Card access can be combined with an identification card, making them less likely to be forgotten or left at home. Key fob devices have the advantage of longer range operation.
Access/ID cards fall into four broad categories: Magnetic stripe cards, proximity cards, proximity smart cards and contact smart cards.
Magnetic stripe cards are the least secure and easiest to duplicate. They are susceptible to damage from ware or by being placed near a magnetic field.
Proximity cards and smart cards are far more resistant to damage or duplication. Smart proximity cards are capable of carrying more information than their access counterparts and can be used for a variety of interactive applications. Some proximity smart cards must incorporate a small battery which can affect the lifespan of the card.
