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 # plonky2
 
-plonky2 is an implementation of recursive arguments based on Plonk and FRI. It is the successor of [plonky](https://github.com/mir-protocol/plonky), which was based on Plonk and Halo.
+plonky2 is an implementation of recursive arguments based on Plonk and FRI. It uses FRI to check systems of polynomial constraints, similar to the DEEP-ALI method described in the [DEEP-FRI](https://arxiv.org/abs/1903.12243) paper. It is the successor of [plonky](https://github.com/mir-protocol/plonky), which was based on Plonk and Halo.
 
-plonky2 is largely focused on recursion performance. We use custom gates to mitigate the bottlenecks of FRI verification, such as hashing and interpolation. We also encode witness data in a ~64 bit field, so field operations take just a few cycles. We use an extension field to boost soundness when needed.
+plonky2 is largely focused on recursion performance. We use custom gates to mitigate the bottlenecks of FRI verification, such as hashing and interpolation. We also encode witness data in a ~64 bit field, so field operations take just a few cycles. To achieve 128-bit security, we repeat certain checks, and run certain parts of the argument in an extension field.
 
 
 ## Running