SIF User Collision

There are limits in SIF about maximum user before problem start to arise. So let's start to discuss about it.

Have you wonder about invite codes? The code that you use to add someone as friend? This one can only hold up to 999999937 unique code (and actually only can hold 999999937 users), or it will start to collide with first user in the SIF, second user, and so on. Basically, that invite code is calculated using this formula (source):

$$ U_ic=(U_id \times 805306357) \mod{999999937} $$

Where:

• \( U_ic \) is the invite code
• \( U_id \) is the user id

Next is user credentials. Believe it or not, your account credentials is stored in keychain. It's in plaintext by default in Android (GameEngineActivity.xml) or in iOS, it's built-in keychain storage. This credentials consist of random characters in UUID form (but actually is not really UUID-compilant) and random 128 hexadecimal character. The UUID also only uses hexadecimal characters, and generated randomly when user is creating account. So the chance of this one collide is 2.935x10^-37 %. How long is it? Very very long, that waiting for the 999999937 invite code limit took less time than waiting this one to collide.

Well, all those thing are depends on environment, bit rot, and the current phase of moon. Maybe when we observe the moon phase to decide when to fasting, that UUID just collide each other, damn.