- #Swtor security key serial number invalid length serial numbers
- #Swtor security key serial number invalid length serial number
The algorithm needn't be cryptographically secure. Those numbers should only account for a small fraction of all the possible numbers of the given length.
#Swtor security key serial number invalid length serial numbers
The generator should only produce serial numbers that pass the test of the checker. I would like to be able to set a salt (and maybe a length).
#Swtor security key serial number invalid length serial number
FFFFE-ttttt plus are device 0x7FFFF.I need a serial number generator and accompanying checker. The 21-19 bits displayed in hex like -00000-ttttt and -00001-ttttt are device 0, -00002-ttttt plus are device 1. TRSM ID (or device id): yes just use sequential numbers. Nowadays KSI has basically become arbitrary, so yes pick what you like.Įxcept I suggest don't use a value that has leading zeros too many things tend to think leading zeros onĪ number-looking (even hex-looking) value are not significant and drop them.
So any cryptogram in the clearing network would self-identify/verify who it "belongs to". Originally the idea was that KSI would identify the bank or subpart of a bank (ATMs, remember) and be globally unique
If you needed much more than 500+ million then I'd worry about it, but by then you'd have enough clout to change this. You can have ABAB00-mmmmm is the first 512K devices for BDK A, ABAB01-mmmmm is the second 512K, etc.,ĪBAB50 is the first batch for BDK B, etc.Īs long as you only need to manage tens or maybe a hundred batches (50+ million devices) this is fine. Which is easier, nothing says different KSIs must always map to different BDKs. So you can shift the other boundary(ies?) if your programs, APIs, partners etc. Technically only the counter part (xx-21) matters to the encryption Originally designed for ATMs that cost many thousands of dollars, so 512K wasn't a troublesome limit You're right nearly everyone seems to use xx-19-21 bits which for 8 bytes is 24-19-21 bits. (or systems) you expect to deal with are limited to 8 bytes, then yes use 8 bytes.Īs below, it's basically arbitrary now anyway. I'm not in a position to say there's a clear pattern either way. The standard has always had KSN 10 bytes (80 bits), but allowed smaller values padded on the left with 0xFF,Īnd many people did or do use 8 bytes. Is there some standard way for setting the TRSM ID? Can I assign TRSM ID = 1 for the very first device injected using a new BDK and then increment it by 1 for each new BDK?Ĩ/10 bytes.Is there some standard way for setting the key set IDs or does every entity owning a BDK come up with its own convention? Can I assign key set ID = 1 to my very first BDK ever and then increment it by 1 for each new BDK? Or is that strategy too naive?.Would you recommend that I just stick to convention? Those implementations would all break if I don’t follow the convention. But I also see many open source implementations of DUKPT that assume 24-19-21 bits split. So I'm tempted to swap the allocation such that we can have up to 500K BDKs and 16M devices. I do read that there is flexibility in how many bits are allocated to key set ID vs TRSM ID. The advantage is that it forces us to not use the same BDK on more than 500K devices which limits exposure of one BDK being compromised. The cons are that I will never have 16M BDKs and if the business is successful it is quite possible to have > 500K devices.
This means around 16M Base Derivation Keys (BDKs) and 500K devices. For an 8 byte KSN the typical convention is 24 bits for key set ID and 19 bits for TRSM ID. KSNs have 3 components: a 21 bits transaction counter and remaining bits are for key set ID and Tamper Resistant Security Module (TRSM) ID.Do I risk being incompatible with some old system if I create 10 bytes long KSNs? Older implementation are 8 bytes whereas newer ones are 10 bytes. I have a number of questions regarding Key Serial Numbers (KSNs) in DUKPT:
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