Protection against cache poisoning

1. A system for protecting computers against cache poisoning, the system comprising:

one or more processors;

a memory accessible by at least one of the processors;

a cache-entity table configured to maintain a plurality of associations between a plurality of data caches and a plurality of entities, wherein each of said data caches is associated with a different one of said entities; and

a cache manager configured to

receive data that is associated with any of said entities and store said received data in any of said data caches that said cache-entity table indicates is associated with said entity;

receive a data request from any of said entities and retrieve said requested data from any of said data caches that said cache-entity table indicates is associated with said requesting entity;

identify any entry that appears in at least a predefined number of said data caches, and move said identified entry from said data caches to a global cache, said global cache separate from said data caches, wherein subsequent data requests for said identified entry are satisfied by retrieving said identified entry directly from said global cache; and

wherein any of said cache-entity table and cache manager are implemented in either of computer hardware and computer software embodied in a computer-readable medium.

2. A system according to claim 1 and further comprising a data request processor configured to provide to said cache manager with any of said data.

3. A system according to claim 2 wherein said data request processor is configured to receive said data request from any of said entities and query said cache manager to determine if said requested data is available from any of said data caches and said global cache.

4. A system according to claim 1 wherein said predefined number of said data caches comprises at least two said data caches.

5. A method for protecting computers against cache poisoning, the method comprising:

maintaining, in a cache-entity table, a plurality of associations between a plurality of data caches and a plurality of entities, wherein each of said data caches is associated with a different one of said entities;

receiving data that is associated with any of said entities;

storing said received data in any of said data caches that said cache-entity table indicates is associated with said entity;

receiving a data request from any of said entities;

retrieving said requested data from any of said data caches that said cache-entity table indicates is associated with said requesting entity; and

identifying any entry that appears in at least a predefined number of said data caches, and moving said identified entry from said data caches to a global cache, said global cache separate from said data caches, wherein subsequent data requests for said identified entry are satisfied by retrieving said identified entry directly from said global cache.

6. A method according to claim 5 wherein said predefined number of said data caches comprises at least two said data caches.

7. A method for protecting computers against cache poisoning, the method comprising:

maintaining, in a cache-entity table, a plurality of associations between a plurality of data caches and a plurality of entities, wherein each of said data caches is associated with a different one of said entities;

receiving data that is associated with any of said entities;

storing said received data in any of said data caches that said cache-entity table indicates is associated with said entity;

identifying any entry that appears in at least a predefined number of said data caches;

moving said entry from said data caches to a global cache, said global cache separate from said data caches;

receiving a data request from any of said entities;

satisfying said data request by retrieving said requested data directly from said global cache if said requested data is in said global cache; and

in response to determining that said requested data is not in said global cache, retrieving said requested data from any of said data caches that said cache-entity table indicates is associated with said requesting entity.

8. A method according to claim 7 wherein said predefined number of said data caches comprises at least two said data caches.

9. A computer program product for protecting computers against cache poisoning, the computer program product comprising:

a computer readable storage medium; and

computer program instructions operative to

maintain, in a cache-entity table, a plurality of associations between a plurality of data caches and a plurality of entities, wherein each of said data caches is associated with a different one of said entities;

receive data that is associated with any of said entities;

store said received data in any of said data caches that said cache-entity table indicates is associated with said entity;

identify any entry that appears in at least a predefined number of said data caches;

move said entry from said data caches to a global cache, said global cache separate from said data caches;

receive a data request from any of said entities;

satisfy said data request by retrieving said requested data directly from said global cache if said requested data is in said global cache; and

retrieve said requested data from any of said data caches that said cache-entity table indicates is associated with said requesting entity if said requested data is not in said global cache,

wherein said program instructions are stored on said computer readable storage medium.

10. A computer program product according to claim 9 wherein said predefined number of said data caches comprises at least two said data caches.