Computer-implemented systems and methods for using a blockchain to perform an atomic swap
Techniques are provided for a computer-implemented security method implemented on one or more blockchains. The method comprises the steps of: applying a one-way function to a first secret value accessible to a first user to create a first veiled secret value; communicating the first veiled secret value from the first user to a second user; receiving a second veiled secret value from the second user, wherein the second veiled secret value is created by applying a one-way function to a second secret value accessible to the second user; and constructing a first blockchain transaction comprising the first veiled secret value and the second veiled secret value, the first blockchain transaction arranged to be unlockable to transfer control of a first resource upon provision of both the first secret value and the second secret value to the first transaction.
1. A computer-implemented security method, the method comprising the steps of, at a first user:
(i) converting a first secret value accessible to a first user into a first masked secret value based on the first secret value and a shared secret value accessible by both the first user and a second user;
(ii) applying a one-way function to the first masked secret value to create a first veiled secret value;
(iii) communicating the first veiled secret value to the second user;
(iv) receiving a second veiled secret value from the second user, wherein the second veiled secret value is created by applying a one-way function to a second masked secret value, and wherein the second masked secret value is based on a second secret value accessible to the second user and on the shared secret value; and
(v) constructing a first blockchain transaction comprising the first veiled secret value and the second veiled secret value, the first blockchain transaction arranged to be unlockable to transfer control of a first resource upon provision of both the first masked secret value and the second masked secret value to the first transaction, wherein a second blockchain transaction comprising the first veiled secret value and the second veiled secret value is arranged to be unlockable to transfer control of a second resource upon provision of both the first masked secret value and the second masked secret value to the second transaction,
wherein unlocking of the first blockchain transaction causes the first secret value to be revealed to the second user, and unlocking of the second blockchain transaction causes the second secret value to be revealed to the first user.
2. The computer-implemented security method according to claim 1 , further comprising creating a first derived public key based on a public key of the first user and a shared secret value accessible to both the first user and the second user, wherein the first blockchain transaction is configured to be redeemable only upon the application of a first private key corresponding to the first derived public key.
3. The computer-implemented security method according to claim 2 , wherein the step of calculating the first derived public key further comprises using a combination of the first and second veiled secret values.
4. The computer-implemented security method according to claim 3 , wherein the combination of the first and second veiled secret values comprises at least one of a concatenation of the first veiled secret value and the second veiled secret value, and a concatenation of at least one veiled secret value with a random or pseudo-random value.
5. The computer-implemented security method according to claim 1 , further comprising the step of constructing at least one of: a third blockchain transaction configured to return control of the first resource to the first user responsive to elapse of a first time period of non-redemption of the first transaction; and a fourth blockchain transaction configured to return control of the second resource to the second user responsive to elapse of a second time period of non-redemption of the second transaction.
6. The computer-implemented security method according to claim 1 , wherein at least one of the first veiled secret value and the second veiled secret value comprises a combination of at least one of the first secret value and the second secret value with a shared secret value accessible by both the first user and second user.
7. The computer-implemented security method according to claim 6 , wherein the shared secret value is established prior to step (i) as a common secret (CS).
8. The computer-implemented security method according to claim 1 , further comprising the following steps:
(vi) generating at least one sequence of veiled secret values starting from at least one of the first secret value and the second secret value;
(vii) executing the method of any preceding claim using at least one of the first secret value and the second secret value; and
(viii) redeeming at least one blockchain transaction to reveal at least one of the first secret value and the second secret value, thereby causing at least one veiled secret value of the sequence to be revealed.
9. The computer-implemented security method according to claim 8 , further comprising the step of executing at least step (v) claim 1 , using at least one veiled secret value revealed in step (viii).
10. The computer-implemented security method according to claim 1 , further comprising:
(vi) converting the first secret value accessible to the first user into the first derived public key, and transmitting the first derived public key to the second user; and
(vii) receiving the second derived public key, wherein the second derived public key is based on a second secret value accessible to the second user.
11. A system, comprising:
one or more processors; and
memory storing instructions executable by the one or more processors to cause the system to perform the method according to claim 1 .
12. A system, comprising: one or more processors; and memory storing instructions executable by the one or more processors to cause the system to perform the method according to claim 1 .
13. A system, comprising:
one or more processors; and
memory storing instructions executable by the one or more processors to cause the system to perform the method according to claim 5 .
14. A system, comprising:
one or more processors; and
memory storing instructions executable by the one or more processors to cause the system to perform the method according to claim 6 .
15. A system, comprising:
one or more processors; and
memory storing instructions executable by the one or more processors to cause the system to perform the method according to claim 9 .
16. One or more non-transitory computer-readable storage media having stored thereon instructions executable by one or more processors of a computer system to cause the computer system to perform the method according to claim 1 .
17. One or more non-transitory computer-readable storage media having stored thereon instructions executable by one or more processors of a computer system to cause the computer system to perform the method according to claim 1 .