<s>
The	O
Apple	B-Device
T2	I-Device
(	O
Apple	O
's	O
internal	O
name	O
is	O
T8012	O
)	O
security	O
chip	O
is	O
a	O
system	B-Architecture
on	I-Architecture
a	I-Architecture
chip	I-Architecture
"	O
SoC	O
"	O
tasked	O
with	O
providing	O
security	O
and	O
controller	O
features	O
to	O
Apple	O
's	O
Intel	B-Device
based	I-Device
Macintosh	B-Device
computers	I-Device
.	O
</s>
<s>
It	O
is	O
a	O
64-bit	B-Device
ARMv8	O
chip	O
and	O
runs	O
bridgeOS	B-Application
.	O
</s>
<s>
The	O
main	O
application	O
processor	O
in	O
T2	O
is	O
a	O
variant	O
of	O
the	O
Apple	O
A10	O
,	O
which	O
is	O
a	O
64-bit	B-Device
ARMv8.1-A	O
based	O
CPU	O
.	O
</s>
<s>
As	O
it	O
serves	O
as	O
a	O
co-processor	O
to	O
its	O
Intel	B-Device
based	I-Device
host	O
,	O
it	O
also	O
consists	O
of	O
several	O
facilities	O
handling	O
a	O
variety	O
of	O
functions	O
not	O
present	O
in	O
the	O
host	O
system	O
's	O
main	O
platform	O
.	O
</s>
<s>
The	O
main	O
application	O
processor	O
in	O
T2	O
is	O
running	O
an	O
operating	B-General_Concept
system	I-General_Concept
called	O
bridgeOS	B-Application
.	O
</s>
<s>
The	O
secondary	O
processor	O
in	O
T2	O
is	O
an	O
32-bit	O
ARMv7-A	O
based	O
CPU	O
called	O
Secure	O
Enclave	O
Processor	O
(	O
SEP	O
)	O
which	O
has	O
the	O
task	O
of	O
generating	O
and	O
storing	O
encryption	B-Application
keys	I-Application
.	O
</s>
<s>
It	O
is	O
running	O
an	O
operating	B-General_Concept
system	I-General_Concept
called	O
"	O
sepOS	O
"	O
based	O
on	O
the	O
L4	B-Operating_System
microkernel	I-Operating_System
.	O
</s>
<s>
The	O
T2	O
module	O
is	O
built	O
as	O
a	O
package	B-Algorithm
on	I-Algorithm
a	I-Algorithm
package	I-Algorithm
(	O
PoP	O
)	O
together	O
with	O
its	O
own	O
2	O
GB	O
LP-DDR4	O
RAM	O
in	O
the	O
case	O
of	O
iMac	B-Device
Pro	I-Device
or	O
1	O
GB	O
in	O
the	O
case	O
of	O
MacBook	B-Device
Pro	I-Device
15	O
"	O
early	O
2019	O
.	O
</s>
<s>
The	O
SEP	O
is	O
used	O
for	O
handling	O
and	O
storing	O
encryption	B-Application
keys	I-Application
,	O
including	O
keys	O
for	O
Touch	O
ID	O
,	O
FileVault	O
,	O
macOS	O
Keychain	B-Application
,	O
and	O
UEFI	B-Architecture
firmware	I-Architecture
passwords	O
.	O
</s>
<s>
An	O
AES	B-Algorithm
Crypto	O
Engine	O
implementing	O
AES-256	B-Algorithm
and	O
a	O
hardware	O
random	O
number	O
generator	O
.	O
</s>
<s>
A	O
Public	B-Application
Key	I-Application
Accelerator	O
is	O
used	O
to	O
perform	O
asymmetric	B-Application
cryptography	I-Application
operations	O
like	O
RSA	B-Architecture
and	O
elliptic-curve	O
cryptography	O
.	O
</s>
<s>
A	O
storage	B-General_Concept
controller	I-General_Concept
for	O
the	O
computer	O
's	O
solid-state	B-Device
drive	I-Device
,	O
including	O
always	O
on	O
,	O
on-the-fly	O
encryption	O
and	O
decryption	O
of	O
data	O
to	O
and	O
from	O
it	O
.	O
</s>
<s>
As	O
a	O
side	O
effect	O
,	O
even	O
if	O
the	O
SSD	B-Device
uses	O
a	O
standardized	O
socket	O
and	O
is	O
not	O
soldered	O
,	O
it	O
still	O
ca	O
n’t	O
be	O
replaced	O
.	O
</s>
<s>
Controllers	O
for	O
microphones	O
,	O
camera	O
,	O
ambient	O
light	O
sensors	O
and	O
Touch	O
ID	O
,	O
decoupling	O
the	O
main	O
operating	B-General_Concept
system	I-General_Concept
's	O
access	O
to	O
those	O
.	O
</s>
<s>
The	O
T2	O
is	O
integral	O
in	O
the	O
boot	B-Operating_System
sequence	I-Operating_System
and	O
upgrading	O
of	O
operating	B-General_Concept
systems	I-General_Concept
,	O
not	O
allowing	O
unsigned	O
components	O
to	O
interfere	O
.	O
</s>
<s>
Image	B-Algorithm
coprocessor	I-Algorithm
enabling	O
accelerated	O
image	B-Algorithm
processing	I-Algorithm
and	O
quality	O
enhancements	O
such	O
as	O
color	B-Algorithm
,	O
exposure	O
balance	O
,	O
and	O
focus	O
for	O
the	O
iMac	B-Device
Pro	I-Device
's	O
FaceTime	B-Operating_System
HD	I-Operating_System
camera	O
.	O
</s>
<s>
Video	B-Application
codec	I-Application
enabling	O
accelerated	O
encoding	O
and	O
decoding	O
of	O
H.264	B-Application
and	O
H.265	B-Algorithm
.	O
</s>
<s>
Controller	O
for	O
a	O
touchscreen	B-Device
,	O
implemented	O
as	O
the	O
Touch	O
Bar	O
in	O
portable	O
Macintosh	B-Device
computers	I-Device
.	O
</s>
<s>
Speaker	B-Device
controller	O
.	O
</s>
<s>
The	O
Apple	B-Device
T2	I-Device
was	O
first	O
released	O
in	O
the	O
iMac	B-Device
Pro	I-Device
in	O
late	O
2017	O
.	O
</s>
<s>
On	O
July	O
12	O
,	O
2018	O
,	O
Apple	O
released	O
an	O
updated	O
MacBook	B-Device
Pro	I-Device
that	O
includes	O
the	O
T2	O
chip	O
,	O
which	O
among	O
other	O
things	O
enables	O
the	O
"	O
Hey	O
Siri	O
"	O
feature	O
.	O
</s>
<s>
On	O
November	O
7	O
,	O
2018	O
,	O
Apple	O
released	O
the	O
updated	O
Mac	B-Device
mini	I-Device
and	O
MacBook	B-Device
Air	I-Device
models	O
with	O
the	O
T2	O
chip	O
.	O
</s>
<s>
MacBook	B-Device
Air	I-Device
’s	O
Touch	O
ID	O
sensor	O
is	O
powered	O
by	O
the	O
chip	O
.	O
</s>
<s>
On	O
August	O
4	O
,	O
2020	O
,	O
a	O
refresh	O
of	O
the	O
5K	O
iMac	B-Device
was	O
announced	O
,	O
including	O
the	O
T2	O
chip	O
.	O
</s>
<s>
The	O
functionality	O
of	O
the	O
T2	O
chip	O
is	O
incorporated	O
in	O
Apple	O
’s	O
M-series	B-Device
CPUs	O
,	O
thus	O
eliminating	O
the	O
need	O
for	O
a	O
separate	O
chip	O
in	O
Apple	O
silicon-powered	O
computers	O
.	O
</s>
<s>
In	O
October	O
2019	O
security	O
researchers	O
began	O
to	O
theorize	O
that	O
the	O
T2	O
might	O
also	O
be	O
affected	O
by	O
the	O
checkm8	O
bug	O
as	O
it	O
was	O
roughly	O
based	O
on	O
the	O
A10	O
design	O
from	O
2016	O
in	O
the	O
original	O
iMac	B-Device
Pro	I-Device
.	O
</s>
<s>
Rick	O
Mark	O
then	O
ported	O
libimobiledevice	O
to	O
work	O
with	O
the	O
Apple	B-Device
T2	I-Device
providing	O
a	O
free	B-License
and	I-License
open	I-License
source	I-License
solution	O
to	O
restoring	O
the	O
T2	O
outside	O
of	O
Apple	B-Operating_System
Configurator	I-Operating_System
and	O
enabling	O
further	O
work	O
on	O
the	O
T2	O
.	O
</s>
<s>
On	O
March	O
6	O
,	O
2020	O
a	O
team	O
of	O
engineers	O
dubbed	O
T2	O
Development	O
Team	O
exploited	O
the	O
existing	O
checkm8	O
bug	O
in	O
the	O
T2	O
and	O
released	O
the	O
hash	O
of	O
a	O
dump	O
of	O
the	O
secure	O
ROM	B-Device
as	O
a	O
proof	O
of	O
entry	O
.	O
</s>
<s>
The	O
checkra1n	O
team	O
quickly	O
integrated	O
the	O
patches	O
required	O
to	O
support	O
jailbreaking	B-Application
the	O
T2	O
.	O
</s>
<s>
This	O
compounded	O
the	O
issue	O
making	O
it	O
possible	O
for	O
any	O
malicious	O
device	O
to	O
jailbreak	B-Application
the	O
T2	O
without	O
any	O
interaction	O
from	O
a	O
custom	O
charging	O
device	O
.	O
</s>
<s>
This	O
had	O
the	O
impact	O
of	O
potentially	O
affecting	O
encrypted	O
credentials	O
such	O
as	O
the	O
FileVault	O
keys	O
as	O
well	O
as	O
other	O
secure	O
Apple	B-Application
Keychain	I-Application
items	O
.	O
</s>
<s>
Developer	O
Rick	O
Mark	O
then	O
determined	O
that	O
macOS	O
could	O
be	O
installed	O
over	O
the	O
same	O
iDevice	O
recovery	O
protocols	O
,	O
which	O
later	O
ended	O
up	O
true	O
of	O
the	O
M1	B-Device
series	O
of	O
Apple	B-Device
Macs	I-Device
.	O
</s>
<s>
On	O
September	O
10	O
,	O
2020	O
a	O
public	O
release	O
of	O
checkra1n	O
was	O
published	O
that	O
allowed	O
users	O
to	O
jailbreak	B-Application
the	O
T2	O
.	O
</s>
<s>
The	O
T2	O
Development	O
Team	O
created	O
patches	O
to	O
remove	O
signature	O
validation	O
from	O
files	O
on	O
the	O
T2	O
such	O
as	O
the	O
MacEFI	O
as	O
well	O
as	O
the	O
boot	B-Operating_System
sound	O
.	O
</s>
<s>
In	O
October	O
2020	O
,	O
a	O
hardware	O
flaw	O
in	O
the	O
chip	O
's	O
security	O
features	O
was	O
found	O
that	O
might	O
be	O
exploited	O
in	O
a	O
way	O
that	O
cannot	O
be	O
patched	O
,	O
using	O
a	O
similar	O
method	O
as	O
the	O
jailbreaking	B-Application
of	O
the	O
iPhone	O
with	O
A10	O
chip	O
,	O
since	O
the	O
T2	O
chip	O
is	O
based	O
on	O
the	O
A10	O
chip	O
.	O
</s>
<s>
It	O
was	O
later	O
demonstrated	O
that	O
this	O
vulnerability	O
can	O
allow	O
users	O
to	O
implement	O
custom	O
Mac	B-Device
startup	I-Device
sounds	I-Device
.	O
</s>
