RFC Errata
RFC 7539, "ChaCha20 and Poly1305 for IETF Protocols", May 2015
Note: This RFC has been obsoleted by RFC 8439
Source of RFC: IRTFSee Also: RFC 7539 w/ inline errata
Errata ID: 4858
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Timm Korte
Date Reported: 2016-11-10
Verifier Name: Lars Eggert
Date Verified: 2016-11-13
Section 2.8. says:
1. The amount of encrypted data possible in a single invocation is 2^32-1 blocks of 64 bytes each, because of the size of the block counter field in the ChaCha20 block function. This gives a total of 247,877,906,880 bytes, or nearly 256 GB.
It should say:
1. The amount of encrypted data possible in a single invocation is 2^32-1 blocks of 64 bytes each, because of the size of the block counter field in the ChaCha20 block function. This gives a total of 274,877,906,880 bytes, or nearly 256 GB.
Notes:
There is an error in the result of the P_MAX = ((2^32) - 1) * 64 calculation.
The correct value is 2_74_,877,906,880 while the document states 2_47_,877,906,880.
This error has already been adopted by multiple implementations as P_MAX value.