Sui Unveils Truncator for Gas-Friendly Post-Quantum Signatures

Every
transaction
and
data
storage
in
a
blockchain
incurs
costs,
including
fees
for
payments,
gas
for
smart
contract
operations,
and
resources
for
data
storage.
Reducing
the
size
of
variables
involved
in
these
transactions,
without
compromising
functionality
or
security,
can
significantly
save
on
communication,
storage,
and
transaction
fees.

Introducing
Truncator

Truncator,
a
mining-based
technique
designed
by
Sui,
reduces
the
size
of
cryptographic
outputs
in
blockchain
systems
without
sacrificing
security,
according
to


The
Sui
Blog.

How
Truncator
Works

Truncator
adds
extra
steps
during
transaction
composition,
resulting
in
significant
benefits
by
reducing
transaction
size
and
associated
gas
costs.
Although
this
process
takes
a
few
seconds,
it
is
beneficial
for
transactions
where
reduced
variable
size
outweighs
the
need
for
speed.
This
approach
helps
reduce
transaction
fees
and
benefits
the
entire
ecosystem
by
lowering
storage
and
communication
costs.

The
Technique
Behind
Truncator

Truncator
involves
an
iterative
search
in
cryptographic
primitives’
inputs
or
randomness
to
find
a
more
efficient
encrypted
output.
This
method
crafts
each
primitive’s
output
to
meet
modified
system
parameters,
such
as
having
specific
bits
of
the
output
constant.
This
is
similar
to
proof-of-work
mechanisms
requiring
miners
to
continually
digest
the
same
data
with
different
random
values
until
meeting
a
specific
system
need,
aiming
to
simplify
the
output.

For
example,
in
the
key
generation
algorithm
for
discrete
logarithm-based
keys,
an
iterative
search
for
a
secret
key
can
ensure
the
derived
public
key
has
a
predetermined
ℓ-bit
prefix,
making
public
keys
smaller
and
reducing
communication
and
storage
costs.

Ensuring
Security

Security
remains
paramount,
and
the
bit-security
framework
shows
that
Truncator
does
not
reduce
key
security.
This
framework
states
that
a
primitive
has
κ-bit
security
if
it
takes
an
adversary
2^κ
operations
to
break
it,
implying
higher
attack
costs
offset
the
reduced
key
space,
maintaining
security
levels.

Real-World
Applications

The
iterative
search
method
to
reduce
the
size
of
keys
and
addresses
has
appeared
before
in
blockchain,
notably
in
Ethereum
proposals
for
“gas
golfing.”
Truncator
formalizes
and
expands
this
idea
to
multiple
cryptographic
primitives,
such
as
hash
digests,
elliptic
curve
cryptography
(ECC)
public
keys,
and
signature
outputs.
For
instance,
about
7%
compression
has
been
achieved
in
less
than
a
second
for
ed25519
signatures
and
under
10
milliseconds
for
compressed
Blake3
digests.
Truncator
has
also
been
explored
for
ElGamal
encryption
and
Diffie-Hellman-based
encryption,
commonly
used
for
blockchain
stealth
addresses.

A
New
Approach
for
Hash-Based
Post-Quantum
Signatures

Truncator’s
techniques
offer
an
opportunity
to
construct
new
cryptographic
schemes,
particularly
for
post-quantum
security.
Hash-based
signature
schemes,
such
as
Lamport
signatures,
are
inherently
quantum-resistant.
Future
schemes
could
incorporate
mining
feasibility,
adjusting
key
generation
to
enhance
resistance
to
quantum
computing
attacks.
Optimizing
key
derivation
in
hash-based
signature
schemes
can
improve
performance
and
efficiency,
crucial
for
maintaining
security
and
usability
in
a
post-quantum
world.

Optimizing
Lamport
Signatures

Optimizing
hash-based
signatures
at
the
key
derivation
level
could
result
in
high-performance
mining
with
better
results
than
brute
forcing.
For
example,
traditional
Lamport
signatures
involve
a
private
key
comprising
256
pairs
of
256-bit
random
values,
totaling
16
KiB.
Each
sub-private
key
corresponds
to
a
public
key,
resulting
in
512
elements.
By
compressing
Lamport
signatures
through
techniques
like
the
Winternitz
hash-chain
variant,
the
number
of
keys
required
for
submission
can
be
reduced,
optimizing
Lamport
verification
and
shortening
proofs.

Conclusion

Truncator
offers
an
innovative
approach
to
reducing
the
output
size
of
cryptographic
primitives,
providing
a
computational
trade-off
that
opens
new
exploration
avenues.
Its
application
to
basic
cryptographic
primitives
and
potential
for
optimizing
hash-based
signatures
at
the
key
derivation
level
has
been
highlighted.
Future
extensions
of
Truncator
could
enhance
efficiency
and
reduce
storage
costs
in
the
blockchain
ecosystem.
Sui
is
particularly
excited
about
incorporating
such
optimizations
into
its
roadmap
for
post-quantum
security,
maintaining
robust
security
standards
while
fostering
innovation.

Image
source:
Shutterstock

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