spec: fix paragraph regarding SUPI

The SUPI often is not larger than the IMSI, but the SUCI is.
This commit is contained in:
Harald Welte 2020-04-16 12:23:34 +02:00
parent 0c7dda618f
commit 29a79afacc
1 changed files with 6 additions and 4 deletions

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@ -32,10 +32,12 @@ reportedly used them to track anybody with a mobile phone.
which uses public-key cryptography to ensure that the permanent subscriber
identity (IMSI) is not transmitted over the air interface anymore.
Rather, a concealed version of it is transmitted (3GPP TS 33.501,
Section 6.12.2). The 5G SUCI mechanism can not be used 1:1 for previous
generations of cellular networks as it relies on extending the
subscriber identity from the small, 15-decimal-digit IMSI to a much
larger SUPI (Subscriber Permanent Identifier) only available in 5G.
Section 6.12.2). The 5G SUCI mechanism can not be adapted easily for previous
generations of cellular networks as it relies on introducing an entirely
new mobile identity type of larger size (SUCI) than any of the existing
ones (e.g. IMSI), causing significant implications on protocol stacks
and implementations all across the protocol stack of all network elements,
including the ME.
No mechanism for increasing subscriber identity and location privacy on
the radio interface has been specified for the previous cellular