I have read too many different options for encryption that I now feel quite lost. I need a simple, secure (don't we all) scheme for encrypting integers (32-bit) with the following requirements:
- Ciphertext is also an integer (32-bit) or a long (64-bit)
- For integers x1=x2 then ciphertexts E(x1)=E(x2)
- For integers x1<>x2 then ciphertexts E(x1)<>E(x2)
- If I know E(x1) it will be very hard to decrypt x1 without the (private) key
Is there such a simple scheme?