We intend to make all the following downloads avaliable eventually. Please send an e-mail if you are interested in obtaining any of the other items.

• Vernam.exe
  A program to encrypt and decrypt data using the Vernam cypher (also known as the one-time pad ). This is the only provably secure cryptosystem known and is used in situations where the highest possible security is required. Click here to download.
  
  
• RBTree
  C source code for a completely generic red-black tree. Click here to download.
  
  
• HTable.c
  C source code for a completely generic externally chained hash table. External chaining has the following advantages when hashing :

1. Performance is not dramatically influenced by overloading the hash table An externally chained hash table has almost identical retrieval and insertion speeds when the load factor is 0.5 and 1.0. With standard hash tables the performance degenerates exponentially as the load factor increases.
2. Deletions do not cause the same difficulties as standard hash tables.
3. The number of elements can be greater than the table size i.e. the load factor can be > 1
4. No need for collision resolution strategies as collisions are fully absorbed by the table.
   HTable.c uses List.c, so please ensure you download this also.

• We hope to also provide C source code implementations of geometric algorithms in the future