Everyone knows about the pascal random()
function.
It returns some numbers, using a linear
congruential generator, with a multiplier of 134775813,
in its Delphi implementation.
It is fast, but not really secure. Output is very predictable, especially if
you forgot to execute the RandSeed()
procedure.
In real world scenarios, safety always requires random numbers, e.g. for
key/nonce/IV/salt/challenge generation.
The less predictable, the better.
We just included a Cryptographically
Secure Pseudo-Random Number Generator (CSPRNG) into our
SynCrypto.pas unit.
The TAESPRNG
class would use real system entropy to generate
a sequence of pseudorandom bytes, using AES-256, so returning highly
unpredictable content.