What the developer wrote
Authored by Ava Chow
kernel: Update headerssync params
What changed, and why it matters
This commit updates the internal tuning numbers used by Bitcoin Core when a new node downloads block headers from the network. It pushes the target date forward by six months and refreshes the generated parameters for mainnet, testnet, testnet4, and signet. There is no bug fix, behavior change, or security patch visible in the diff—it is routine parameter maintenance.
No security action needed. Treat as normal consensus/network parameter maintenance.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The change updates the headerssync-params.py script’s TIME horizon from 2028-04-02 to 2028-10-10 and MINCHAINWORK_HEADERS from 912683 to 938343, then regenerates the resulting HeadersSyncParams (commitment_period and redownload_buffer_size) for all four chain configurations. The ratios between buffer size and commitment period stay roughly the same, indicating a routine re-derivation rather than a security-relevant algorithmic change.
Changed components
src/kernel/chainparams.cppcontrib/devtools/headerssync-params.pyInspect captured patch +14 / −14
diff --git a/contrib/devtools/headerssync-params.py b/contrib/devtools/headerssync-params.py
index 82bdaadb..886ea583 100755
--- a/contrib/devtools/headerssync-params.py
+++ b/contrib/devtools/headerssync-params.py
@@ -12,13 +12,13 @@ import random
# Parameters:
# Aim for still working fine at some point in the future. [datetime]
-TIME = datetime(2028, 4, 2)
+TIME = datetime(2028, 10, 10)
# Expected block interval. [timedelta]
BLOCK_INTERVAL = timedelta(seconds=600)
# The number of headers corresponding to the minchainwork parameter. [headers]
-MINCHAINWORK_HEADERS = 912683
+MINCHAINWORK_HEADERS = 938343
# Combined processing bandwidth from all attackers to one victim. [bit/s]
# 6 Gbit/s is approximately the speed at which a single thread of a Ryzen 5950X CPU thread can hash
diff --git a/src/kernel/chainparams.cpp b/src/kernel/chainparams.cpp
index c94cb8c4..3571b500 100644
--- a/src/kernel/chainparams.cpp
+++ b/src/kernel/chainparams.cpp
@@ -191,10 +191,10 @@ public:
.dTxRate = 5.40111006496122,
};
- // Generated by headerssync-params.py on 2025-09-01.
+ // Generated by headerssync-params.py on 2026-02-25.
m_headers_sync_params = HeadersSyncParams{
- .commitment_period = 632,
- .redownload_buffer_size = 15009, // 15009/632 = ~23.7 commitments
+ .commitment_period = 641,
+ .redownload_buffer_size = 15218, // 15218/641 = ~23.7 commitments
};
}
};
@@ -294,10 +294,10 @@ public:
.dTxRate = 0.02691479016257117,
};
- // Generated by headerssync-params.py on 2025-09-03.
+ // Generated by headerssync-params.py on 2026-02-25.
m_headers_sync_params = HeadersSyncParams{
- .commitment_period = 628,
- .redownload_buffer_size = 13460, // 13460/628 = ~21.4 commitments
+ .commitment_period = 673,
+ .redownload_buffer_size = 14460, // 14460/673 = ~21.5 commitments
};
}
};
@@ -401,10 +401,10 @@ public:
.dTxRate = 0.01848579579528412,
};
- // Generated by headerssync-params.py on 2025-09-03.
+ // Generated by headerssync-params.py on 2026-02-25.
m_headers_sync_params = HeadersSyncParams{
- .commitment_period = 275,
- .redownload_buffer_size = 7017, // 7017/275 = ~25.5 commitments
+ .commitment_period = 606,
+ .redownload_buffer_size = 16092, // 16092/606 = ~26.6 commitments
};
}
};
@@ -520,10 +520,10 @@ public:
fDefaultConsistencyChecks = false;
m_is_mockable_chain = false;
- // Generated by headerssync-params.py on 2025-09-03.
+ // Generated by headerssync-params.py on 2026-02-25.
m_headers_sync_params = HeadersSyncParams{
- .commitment_period = 390,
- .redownload_buffer_size = 9584, // 9584/390 = ~24.6 commitments
+ .commitment_period = 620,
+ .redownload_buffer_size = 15724, // 15724/620 = ~25.4 commitments
};
}
};
Why this scored 15/100
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