Revision History for: Quantum Digital Signature
- 2026-06-07 at 18:59 by Mina Doosti
Functionality Description
Digital Signatures (QDS) allow the exchange of classical messages from sender to multiple recipients, with a guarantee that the signature has come from a genuine sender. Additionally, it comes with the properties of transferability, non-repudiation and unforgeability. In contrast, classical digital signatures rely on authentication (taken as an assumption for some QDS protocols) i.e. the message has come from the claimed party; integrity i.e. the message has not been altered (if authentication is confirmed, this property is unforgeability) and non-repudiation (same as QDS). These properties distinguish quantum digital signatures from quantum authentication. Quantum messages can be authenticated but not signed [1], [2]. Note that QDS schemes sign classical messages and not quantum messages.
Protocols
The protocols that implement this functionality are:
Classical Analogues
No content has been added to this section, yet!
Real-world Use Cases
No content has been added to this section, yet!
Properties
All QDS protocols are divided into two phases, distribution and messaging. Distribution phase enables sender to generate private keys (kept secret with sender) and public keys (information distributed to recipients) while messaging phase enables exchange of messages using the above keys. For simplicity, most protocols use the case of three parties, one sender (Seller) and two recipients (Buyer and Verifier) exchanging one-bit classical messages signed by Quantum Digital Signatures (QDS).
- A QDS scheme is correct if a message signed by a genuine sender is accepted by a recipient with unit probability.
- A QDS scheme is secure if no one but the sender can sign a message such that it is accepted by a recipient with non-negligible probability.
- Transferability means that at any point a recipient (buyer) can prove it to another recipient (verifier) that the concerned message has been signed by the claimed sender (Seller).
- Unforgeability ensures that a dishonest recipient (buyer) can neither alter a DS nor sign a message with a fake DS (DS that has not come from a genuine sender) and forward it to other recipients (verifier) successfully.
- Non-Repudiation implies that at any point a dishonest sender (seller) cannot deny having signed the message sent to a genuine recipient (Buyer).
Further Information
Unlike classical digital signature schemes which generalize a two party model, QDS protocols always study a three party model as transferability is not inherent and has to be proved in the quantum case. Given this situation, usually, the third party acts as the judge (a verififer) who would gain nothing out of cheating, and hence, cheating strategy is only studied for seller (repudiation) and buyer (forgery). Quantum digital signatures provide unconditional security, not relying on any computational assumption which is its basic advantage over the classical schemes. However, over time classical unconditionally secure digital signature schemes have been realized. These classical protocols take extra some assumptions like trusted omnipotent (one who distributes everyone signatures) or authenticated message broadcast. QDS does not require any such assumption. Yet, the low key rate could render QDS impractical over classical digital signature schemes. At the same time, there exist post quantum secure Digital signature schemes based on hash-key cryptography which cannot be broken by quantum computers. Still, if someone requires a lifetime security without the above mentioned assumptions, QDS is the answer. Areas to improve QDS could be addressing the key rate and scalability of key length with length of message. Following are a few articles useful for those interested in a more detailed overview of QDS.
Some review papers:
- [3]: Discusses various classical and quantum digital signature schemes.
- [4]: Discusses the development of Quantum Digital Signatures from the first protocol by Gottesman and Chuang, elaborating advancements in further protocols to turn it into a practical QDS scheme.
References
* The original version of this page on the old QPZoo was created by Shraddha Singh.
- Barnum, Howard, Claude Crépeau, Daniel Gottesman, Adam Smith, and Alain Tapp. “Authentication of quantum messages.” In The 43rd Annual IEEE Symposium on Foundations of Computer Science, 2002. Proceedings., pp. 449-458. IEEE, 2002.
- Li, Qin, Wai Hong Chan, Chunhui Wu, and Zhonghua Wen. “On the existence of quantum signature for quantum messages.” International Journal of Theoretical Physics 52 (2013): 4335-4341.
- Amiri, Ryan, and Erika Andersson. “Unconditionally secure quantum signatures.” Entropy 17, no. 8 (2015): 5635-5659.
- [Wallden P. (2018)] acheck
- 2025-06-24 at 21:25 by JuliaM
Functionality Description
Digital Signatures (QDS) allow the exchange of classical messages from sender to multiple recipients, with a guarantee that the signature has come from a genuine sender. Additionally, it comes with the properties of transferability, non-repudiation and unforgeability. In contrast, classical digital signatures rely on authentication (taken as an assumption for some QDS protocols) i.e. the message has come from the claimed party; integrity i.e. the message has not been altered (if authentication is confirmed, this property is unforgeability) and non-repudiation (same as QDS). These properties distinguish quantum digital signatures from quantum authentication. Quantum messages can be authenticated but not signed [1], [2]. Note that QDS schemes sign classical messages and not quantum messages.
Protocols
The protocols that implement this functionality are:
Classical Analogues
No content has been added to this section, yet!
Real-world Use Cases
No content has been added to this section, yet!
Properties
All QDS protocols are divided into two phases, distribution and messaging. Distribution phase enables sender to generate private keys (kept secret with sender) and public keys (information distributed to recipients) while messaging phase enables exchange of messages using the above keys. For simplicity, most protocols use the case of three parties, one sender (Seller) and two recipients (Buyer and Verifier) exchanging one-bit classical messages signed by Quantum Digital Signatures (QDS).
- A QDS scheme is correct if a message signed by a genuine sender is accepted by a recipient with unit probability.
- A QDS scheme is secure if no one but the sender can sign a message such that it is accepted by a recipient with non-negligible probability.
- Transferability means that at any point a recipient (buyer) can prove it to another recipient (verifier) that the concerned message has been signed by the claimed sender (Seller).
- Unforgeability ensures that a dishonest recipient (buyer) can neither alter a DS nor sign a message with a fake DS (DS that has not come from a genuine sender) and forward it to other recipients (verifier) successfully.
- Non-Repudiation implies that at any point a dishonest sender (seller) cannot deny having signed the message sent to a genuine recipient (Buyer).
Further Information
Unlike classical digital signature schemes which generalize a two party model, QDS protocols always study a three party model as transferability is not inherent and has to be proved in the quantum case. Given this situation, usually, the third party acts as the judge (a verififer) who would gain nothing out of cheating, and hence, cheating strategy is only studied for seller (repudiation) and buyer (forgery). Quantum digital signatures provide unconditional security, not relying on any computational assumption which is its basic advantage over the classical schemes. However, over time classical unconditionally secure digital signature schemes have been realized. These classical protocols take extra some assumptions like trusted omnipotent (one who distributes everyone signatures) or authenticated message broadcast. QDS does not require any such assumption. Yet, the low key rate could render QDS impractical over classical digital signature schemes. At the same time, there exist post quantum secure Digital signature schemes based on hash-key cryptography which cannot be broken by quantum computers. Still, if someone requires a lifetime security without the above mentioned assumptions, QDS is the answer. Areas to improve QDS could be addressing the key rate and scalability of key length with length of message. Following are a few articles useful for those interested in a more detailed overview of QDS.
Some review papers:
- [3]: Discusses various classical and quantum digital signature schemes.
- [4]: Discusses the development of Quantum Digital Signatures from the first protocol by Gottesman and Chuang, elaborating advancements in further protocols to turn it into a practical QDS scheme.
References
- Barnum, Howard, Claude Crépeau, Daniel Gottesman, Adam Smith, and Alain Tapp. “Authentication of quantum messages.” In The 43rd Annual IEEE Symposium on Foundations of Computer Science, 2002. Proceedings., pp. 449-458. IEEE, 2002.
- Li, Qin, Wai Hong Chan, Chunhui Wu, and Zhonghua Wen. “On the existence of quantum signature for quantum messages.” International Journal of Theoretical Physics 52 (2013): 4335-4341.
- Amiri, Ryan, and Erika Andersson. “Unconditionally secure quantum signatures.” Entropy 17, no. 8 (2015): 5635-5659.
- [Wallden P. (2018)] acheck
- 2025-05-15 at 13:04 by JuliaM
Functionality Description
Digital Signatures (QDS) allow the exchange of classical messages from sender to multiple recipients, with a guarantee that the signature has come from a genuine sender. Additionally, it comes with the properties of transferability, non-repudiation and unforgeability. In contrast, classical digital signatures rely on authentication (taken as an assumption for some QDS protocols) i.e. the message has come from the claimed party; integrity i.e. the message has not been altered (if authentication is confirmed, this property is unforgeability) and non-repudiation (same as QDS). These properties distinguish quantum digital signatures from quantum authentication. Quantum messages can be authenticated but not signed [1], [2]. Note that QDS schemes sign classical messages and not quantum messages.
Protocols
No protocols implement this functionality yet.
Classical Analogues
acheck
Real-world Use Cases
acheck
Properties
All QDS protocols are divided into two phases, distribution and messaging. Distribution phase enables sender to generate private keys (kept secret with sender) and public keys (information distributed to recipients) while messaging phase enables exchange of messages using the above keys. For simplicity, most protocols use the case of three parties, one sender (Seller) and two recipients (Buyer and Verifier) exchanging one-bit classical messages signed by Quantum Digital Signatures (QDS).
- A QDS scheme is correct if a message signed by a genuine sender is accepted by a recipient with unit probability.
- A QDS scheme is secure if no one but the sender can sign a message such that it is accepted by a recipient with non-negligible probability.
- Transferability means that at any point a recipient (buyer) can prove it to another recipient (verifier) that the concerned message has been signed by the claimed sender (Seller).
- Unforgeability ensures that a dishonest recipient (buyer) can neither alter a DS nor sign a message with a fake DS (DS that has not come from a genuine sender) and forward it to other recipients (verifier) successfully.
- Non-Repudiation implies that at any point a dishonest sender (seller) cannot deny having signed the message sent to a genuine recipient (Buyer).
Further Information
Unlike classical digital signature schemes which generalize a two party model, QDS protocols always study a three party model as transferability is not inherent and has to be proved in the quantum case. Given this situation, usually, the third party acts as the judge (a verififer) who would gain nothing out of cheating, and hence, cheating strategy is only studied for seller (repudiation) and buyer (forgery). Quantum digital signatures provide unconditional security, not relying on any computational assumption which is its basic advantage over the classical schemes. However, over time classical unconditionally secure digital signature schemes have been realized. These classical protocols take extra some assumptions like trusted omnipotent (one who distributes everyone signatures) or authenticated message broadcast. QDS does not require any such assumption. Yet, the low key rate could render QDS impractical over classical digital signature schemes. At the same time, there exist post quantum secure Digital signature schemes based on hash-key cryptography which cannot be broken by quantum computers. Still, if someone requires a lifetime security without the above mentioned assumptions, QDS is the answer. Areas to improve QDS could be addressing the key rate and scalability of key length with length of message. Following are a few articles useful for those interested in a more detailed overview of QDS.
Some review papers:
- [3]: Discusses various classical and quantum digital signature schemes.
- [4]: Discusses the development of Quantum Digital Signatures from the first protocol by Gottesman and Chuang, elaborating advancements in further protocols to turn it into a practical QDS scheme.
References
- Barnum, Howard, Claude Crépeau, Daniel Gottesman, Adam Smith, and Alain Tapp. “Authentication of quantum messages.” In The 43rd Annual IEEE Symposium on Foundations of Computer Science, 2002. Proceedings., pp. 449-458. IEEE, 2002.
- Li, Qin, Wai Hong Chan, Chunhui Wu, and Zhonghua Wen. “On the existence of quantum signature for quantum messages.” International Journal of Theoretical Physics 52 (2013): 4335-4341.
- Amiri, Ryan, and Erika Andersson. “Unconditionally secure quantum signatures.” Entropy 17, no. 8 (2015): 5635-5659.
- [Wallden P. (2018)] acheck
- 2025-05-15 at 13:03 by JuliaM