SLIDE 1 Quantum circuits for the CSIDH:
- ptimizing quantum evaluation
- f isogenies
Daniel J. Bernstein Tanja Lange Chloe Martindale Lorenz Panny quantum.isogeny.org
SLIDE 2
Key bits where all known attacks take 2λ operations (naive serial attack metric, ignoring memory cost): pre-quantum post-quantum SIDH, SIKE (24 + o(1))λ (36 + o(1))λ compressed (14 + o(1))λ (21 + o(1))λ CRS, CSIDH (4 + o(1))λ superlinear
SLIDE 3
Key bits where all known attacks take 2λ operations (naive serial attack metric, ignoring memory cost): pre-quantum post-quantum SIDH, SIKE (24 + o(1))λ (36 + o(1))λ compressed (14 + o(1))λ (21 + o(1))λ CRS, CSIDH (4 + o(1))λ superlinear For which λ does this cross (21 + o(1))λ?
SLIDE 4
Key bits where all known attacks take 2λ operations (naive serial attack metric, ignoring memory cost): pre-quantum post-quantum SIDH, SIKE (24 + o(1))λ (36 + o(1))λ compressed (14 + o(1))λ (21 + o(1))λ CRS, CSIDH (4 + o(1))λ superlinear For which λ does this cross (21 + o(1))λ? Subexp 2010 Childs–Jao–Soukharev attack, using 2003 Kuperberg or 2004 Regev or 2011 Kuperberg.
SLIDE 5 Key bits where all known attacks take 2λ operations (naive serial attack metric, ignoring memory cost): pre-quantum post-quantum SIDH, SIKE (24 + o(1))λ (36 + o(1))λ compressed (14 + o(1))λ (21 + o(1))λ CRS, CSIDH (4 + o(1))λ superlinear For which λ does this cross (21 + o(1))λ? Subexp 2010 Childs–Jao–Soukharev attack, using 2003 Kuperberg or 2004 Regev or 2011 Kuperberg.
- How many queries do these attacks perform?
SLIDE 6 Key bits where all known attacks take 2λ operations (naive serial attack metric, ignoring memory cost): pre-quantum post-quantum SIDH, SIKE (24 + o(1))λ (36 + o(1))λ compressed (14 + o(1))λ (21 + o(1))λ CRS, CSIDH (4 + o(1))λ superlinear For which λ does this cross (21 + o(1))λ? Subexp 2010 Childs–Jao–Soukharev attack, using 2003 Kuperberg or 2004 Regev or 2011 Kuperberg.
- How many queries do these attacks perform?
- How expensive is each CSIDH query?
SLIDE 7 Key bits where all known attacks take 2λ operations (naive serial attack metric, ignoring memory cost): pre-quantum post-quantum SIDH, SIKE (24 + o(1))λ (36 + o(1))λ compressed (14 + o(1))λ (21 + o(1))λ CRS, CSIDH (4 + o(1))λ superlinear For which λ does this cross (21 + o(1))λ? Subexp 2010 Childs–Jao–Soukharev attack, using 2003 Kuperberg or 2004 Regev or 2011 Kuperberg.
- How many queries do these attacks perform?
- How expensive is each CSIDH query?
Our 56-page paper: see quantum.isogeny.org.
SLIDE 8 Key bits where all known attacks take 2λ operations (naive serial attack metric, ignoring memory cost): pre-quantum post-quantum SIDH, SIKE (24 + o(1))λ (36 + o(1))λ compressed (14 + o(1))λ (21 + o(1))λ CRS, CSIDH (4 + o(1))λ superlinear For which λ does this cross (21 + o(1))λ? Subexp 2010 Childs–Jao–Soukharev attack, using 2003 Kuperberg or 2004 Regev or 2011 Kuperberg.
- How many queries do these attacks perform?
- How expensive is each CSIDH query?
Our 56-page paper: see quantum.isogeny.org.
- What about memory, using parallel AT metric?
SLIDE 9
Case study: attacking CSIDH-512
CSIDH-512 query, uniform over {−5, . . . , 5}74, failure chance <2−32 (maybe ok), nonlinear bit ops: ≈251 by 2018 Jao–LeGrow–Leonardi–Ruiz-Lopez.
SLIDE 10
Case study: attacking CSIDH-512
CSIDH-512 query, uniform over {−5, . . . , 5}74, failure chance <2−32 (maybe ok), nonlinear bit ops: ≈251 by 2018 Jao–LeGrow–Leonardi–Ruiz-Lopez. 1118827416420 ≈ 240 by our Algorithm 7.1.
SLIDE 11
Case study: attacking CSIDH-512
CSIDH-512 query, uniform over {−5, . . . , 5}74, failure chance <2−32 (maybe ok), nonlinear bit ops: ≈251 by 2018 Jao–LeGrow–Leonardi–Ruiz-Lopez. 1118827416420 ≈ 240 by our Algorithm 7.1. 765325228976 ≈ 0.7 · 240 by our Algorithm 8.1. Generic conversion to quantum computation: ≈243.3 T-gates using ≈240 qubits.
SLIDE 12
Case study: attacking CSIDH-512
CSIDH-512 query, uniform over {−5, . . . , 5}74, failure chance <2−32 (maybe ok), nonlinear bit ops: ≈251 by 2018 Jao–LeGrow–Leonardi–Ruiz-Lopez. 1118827416420 ≈ 240 by our Algorithm 7.1. 765325228976 ≈ 0.7 · 240 by our Algorithm 8.1. Generic conversion to quantum computation: ≈243.3 T-gates using ≈240 qubits. Can do ≈245.3 T-gates using ≈220 qubits.
SLIDE 13
Case study: attacking CSIDH-512
CSIDH-512 query, uniform over {−5, . . . , 5}74, failure chance <2−32 (maybe ok), nonlinear bit ops: ≈251 by 2018 Jao–LeGrow–Leonardi–Ruiz-Lopez. 1118827416420 ≈ 240 by our Algorithm 7.1. 765325228976 ≈ 0.7 · 240 by our Algorithm 8.1. Generic conversion to quantum computation: ≈243.3 T-gates using ≈240 qubits. Can do ≈245.3 T-gates using ≈220 qubits. Total gates (T+Clifford): ≈246.9.
SLIDE 14
Case study: attacking CSIDH-512
CSIDH-512 query, uniform over {−5, . . . , 5}74, failure chance <2−32 (maybe ok), nonlinear bit ops: ≈251 by 2018 Jao–LeGrow–Leonardi–Ruiz-Lopez. 1118827416420 ≈ 240 by our Algorithm 7.1. 765325228976 ≈ 0.7 · 240 by our Algorithm 8.1. Generic conversion to quantum computation: ≈243.3 T-gates using ≈240 qubits. Can do ≈245.3 T-gates using ≈220 qubits. Total gates (T+Clifford): ≈246.9. BS18 claim only ≈22 lattice overhead per query. BS18 claim only ≈232.5 queries using ≈231 qubits.
SLIDE 15
Case study: attacking CSIDH-512
CSIDH-512 query, uniform over {−5, . . . , 5}74, failure chance <2−32 (maybe ok), nonlinear bit ops: ≈251 by 2018 Jao–LeGrow–Leonardi–Ruiz-Lopez. 1118827416420 ≈ 240 by our Algorithm 7.1. 765325228976 ≈ 0.7 · 240 by our Algorithm 8.1. Generic conversion to quantum computation: ≈243.3 T-gates using ≈240 qubits. Can do ≈245.3 T-gates using ≈220 qubits. Total gates (T+Clifford): ≈246.9. BS18 claim only ≈22 lattice overhead per query. BS18 claim only ≈232.5 queries using ≈231 qubits. If these claims are correct: ≈281.4 total gates.
SLIDE 16
Case study: attacking CSIDH-512
CSIDH-512 query, uniform over {−5, . . . , 5}74, failure chance <2−32 (maybe ok), nonlinear bit ops: ≈251 by 2018 Jao–LeGrow–Leonardi–Ruiz-Lopez. 1118827416420 ≈ 240 by our Algorithm 7.1. 765325228976 ≈ 0.7 · 240 by our Algorithm 8.1. Generic conversion to quantum computation: ≈243.3 T-gates using ≈240 qubits. Can do ≈245.3 T-gates using ≈220 qubits. Total gates (T+Clifford): ≈246.9. BS18 claim only ≈22 lattice overhead per query. BS18 claim only ≈232.5 queries using ≈231 qubits. If these claims are correct: ≈281.4 total gates. BS18 claim 271 total gates. We explain gap.