diff --git a/chain/gen/gen.go b/chain/gen/gen.go
index d75215083..71a7f3127 100644
--- a/chain/gen/gen.go
+++ b/chain/gen/gen.go
@@ -12,7 +12,6 @@ import (
 	commcid "github.com/filecoin-project/go-fil-commcid"
 	"github.com/filecoin-project/specs-actors/actors/abi"
 	"github.com/filecoin-project/specs-actors/actors/crypto"
-	"github.com/filecoin-project/specs-storage/storage"
 	block "github.com/ipfs/go-block-format"
 	"github.com/ipfs/go-blockservice"
 	"github.com/ipfs/go-car"
@@ -65,7 +64,7 @@ type ChainGen struct {
 
 	w *wallet.Wallet
 
-	eppProvs    map[address.Address]ElectionPoStProver
+	eppProvs    map[address.Address]WinningPoStProver
 	Miners      []address.Address
 	receivers   []address.Address
 	banker      address.Address
@@ -205,9 +204,9 @@ func NewGenerator() (*ChainGen, error) {
 		return nil, xerrors.Errorf("set genesis failed: %w", err)
 	}
 
-	mgen := make(map[address.Address]ElectionPoStProver)
+	mgen := make(map[address.Address]WinningPoStProver)
 	for i := range tpl.Miners {
-		mgen[genesis2.MinerAddress(uint64(i))] = &eppProvider{}
+		mgen[genesis2.MinerAddress(uint64(i))] = &wppProvider{}
 	}
 
 	sm := stmgr.NewStateManager(cs)
@@ -501,39 +500,28 @@ func (mca mca) WalletSign(ctx context.Context, a address.Address, v []byte) (*cr
 	return mca.w.Sign(ctx, a, v)
 }
 
-type ElectionPoStProver interface {
-	GenerateCandidates(context.Context, []abi.SectorInfo, abi.PoStRandomness) ([]storage.PoStCandidateWithTicket, error)
-	ComputeProof(context.Context, []abi.SectorInfo, []byte, []storage.PoStCandidateWithTicket) ([]abi.PoStProof, error)
+type WinningPoStProver interface {
+	GenerateCandidates(context.Context, abi.PoStRandomness, uint64) ([]uint64, error)
+	ComputeProof(context.Context, []abi.SectorInfo, []byte) ([]abi.PoStProof, error)
 }
 
-type eppProvider struct{}
+type wppProvider struct{}
 
-func (epp *eppProvider) GenerateCandidates(ctx context.Context, _ []abi.SectorInfo, eprand abi.PoStRandomness) ([]storage.PoStCandidateWithTicket, error) {
-	return []storage.PoStCandidateWithTicket{
-		{
-			Candidate: abi.PoStCandidate{
-				RegisteredProof: abi.RegisteredProof_StackedDRG2KiBPoSt,
-				SectorID:        abi.SectorID{Number: 1},
-				PartialTicket:   abi.PartialTicket{},
-				PrivateProof:    abi.PrivatePoStCandidateProof{},
-				ChallengeIndex:  1,
-			},
-		},
-	}, nil
+func (wpp *wppProvider) GenerateCandidates(ctx context.Context, _ abi.PoStRandomness, _ uint64) ([]uint64, error) {
+	return []uint64{0}, nil
 }
 
-func (epp *eppProvider) ComputeProof(ctx context.Context, _ []abi.SectorInfo, eprand []byte, winners []storage.PoStCandidateWithTicket) ([]abi.PoStProof, error) {
-
+func (wpp *wppProvider) ComputeProof(context.Context, []abi.SectorInfo, []byte) ([]abi.PoStProof, error) {
 	return []abi.PoStProof{{
 		ProofBytes: []byte("valid proof"),
 	}}, nil
 }
 
 type ProofInput struct {
-	sectors []abi.SectorInfo
-	hvrf    []byte
-	winners []storage.PoStCandidateWithTicket
-	vrfout  []byte
+	sectors           []abi.SectorInfo
+	hvrf              []byte
+	challengedSectors []uint64
+	vrfout            []byte
 }
 
 func IsRoundWinner(ctx context.Context, ts *types.TipSet, round abi.ChainEpoch,
@@ -563,8 +551,8 @@ func IsRoundWinner(ctx context.Context, ts *types.TipSet, round abi.ChainEpoch,
 }
 
 /*
-func ComputeProof(ctx context.Context, epp ElectionPoStProver, pi *ProofInput) (*types.EPostProof, error) {
-	proof, err := epp.ComputeProof(ctx, pi.sectors, pi.hvrf, pi.winners)
+func ComputeProof(ctx context.Context, epp WinningPoStProver, pi *ProofInput) (*types.EPostProof, error) {
+	proof, err := epp.ComputeProof(ctx, pi.sectors, pi.hvrf, pi.challengedSectors)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to compute snark for election proof: %w", err)
 	}
@@ -573,7 +561,7 @@ func ComputeProof(ctx context.Context, epp ElectionPoStProver, pi *ProofInput) (
 		Proofs:   proof,
 		PostRand: pi.vrfout,
 	}
-	for _, win := range pi.winners {
+	for _, win := range pi.challengedSectors {
 		part := make([]byte, 32)
 		copy(part, win.Candidate.PartialTicket)
 		ept.Candidates = append(ept.Candidates, types.EPostTicket{
@@ -622,14 +610,14 @@ type genFakeVerifier struct{}
 
 var _ ffiwrapper.Verifier = (*genFakeVerifier)(nil)
 
-func (m genFakeVerifier) VerifyElectionPost(ctx context.Context, pvi abi.PoStVerifyInfo) (bool, error) {
-	panic("nyi")
-}
-
 func (m genFakeVerifier) VerifySeal(svi abi.SealVerifyInfo) (bool, error) {
 	return true, nil
 }
 
-func (m genFakeVerifier) VerifyFallbackPost(ctx context.Context, pvi abi.PoStVerifyInfo) (bool, error) {
-	panic("nyi")
+func (m genFakeVerifier) VerifyWinningPoSt(ctx context.Context, info abi.WinningPoStVerifyInfo) (bool, error) {
+	panic("implement me")
+}
+
+func (m genFakeVerifier) VerifyWindowPoSt(ctx context.Context, info abi.WindowPoStVerifyInfo) (bool, error) {
+	panic("implement me")
 }
diff --git a/chain/gen/genesis/miners.go b/chain/gen/genesis/miners.go
index cd0d6b7ce..01d962a8f 100644
--- a/chain/gen/genesis/miners.go
+++ b/chain/gen/genesis/miners.go
@@ -6,19 +6,19 @@ import (
 	"fmt"
 	"math/rand"
 
-	cborutil "github.com/filecoin-project/go-cbor-util"
-	"github.com/filecoin-project/specs-actors/actors/builtin/power"
+	"github.com/ipfs/go-cid"
 	cbor "github.com/ipfs/go-ipld-cbor"
+	"golang.org/x/xerrors"
 
 	"github.com/filecoin-project/go-address"
+	cborutil "github.com/filecoin-project/go-cbor-util"
 	"github.com/filecoin-project/specs-actors/actors/abi"
 	"github.com/filecoin-project/specs-actors/actors/abi/big"
 	"github.com/filecoin-project/specs-actors/actors/builtin"
 	"github.com/filecoin-project/specs-actors/actors/builtin/market"
 	"github.com/filecoin-project/specs-actors/actors/builtin/miner"
+	"github.com/filecoin-project/specs-actors/actors/builtin/power"
 	"github.com/filecoin-project/specs-actors/actors/crypto"
-	"github.com/ipfs/go-cid"
-	"golang.org/x/xerrors"
 
 	"github.com/filecoin-project/lotus/build"
 	"github.com/filecoin-project/lotus/chain/state"
@@ -182,7 +182,7 @@ func SetupStorageMiners(ctx context.Context, cs *store.ChainStore, sroot cid.Cid
 					}
 
 					// TODO: This is almost definitely not correct
-					circSupply := types.BigMul(types.NewInt(build.TotalFilecoin - build.MiningRewardTotal), types.NewInt(build.FilecoinPrecision))
+					circSupply := types.BigMul(types.NewInt(build.TotalFilecoin-build.MiningRewardTotal), types.NewInt(build.FilecoinPrecision))
 					totalPledge := types.NewInt(3)
 					perEpochReward := types.NewInt(9)
 
diff --git a/chain/gen/genesis/t04_power.go b/chain/gen/genesis/t04_power.go
index ac7af899c..146e08f7d 100644
--- a/chain/gen/genesis/t04_power.go
+++ b/chain/gen/genesis/t04_power.go
@@ -24,7 +24,7 @@ func SetupStoragePowerActor(bs bstore.Blockstore) (*types.Actor, error) {
 	}
 
 	sms := &power.State{
-		TotalQualityAdjPower:        big.NewInt(1), // TODO: has to be 1 initially to avoid div by zero. Kinda annoying, should find a way to fix
+		TotalQualityAdjPower:     big.NewInt(1), // TODO: has to be 1 initially to avoid div by zero. Kinda annoying, should find a way to fix
 		MinerCount:               0,
 		EscrowTable:              emptyhamt,
 		CronEventQueue:           emptyhamt,
diff --git a/cmd/lotus-bench/main.go b/cmd/lotus-bench/main.go
index 0d5289119..b2e24b96a 100644
--- a/cmd/lotus-bench/main.go
+++ b/cmd/lotus-bench/main.go
@@ -174,7 +174,7 @@ var sealBenchCmd = &cli.Command{
 		}
 		sectorSize := abi.SectorSize(sectorSizeInt)
 
-		_, spt, err := ffiwrapper.ProofTypeFromSectorSize(sectorSize)
+		_, spt, err := ffiwrapper.SealProofTypeFromSectorSize(sectorSize)
 		if err != nil {
 			return err
 		}
@@ -401,7 +401,8 @@ var sealBenchCmd = &cli.Command{
 
 			candidates := make([]abi.SectorInfo, len(fcandidates))
 			for i, fcandidate := range fcandidates {
-				candidates[i] = sealedSectors[i]; _ = fcandidate // todo: I have no idea what is under fcandidate, but it's a large number
+				candidates[i] = sealedSectors[i]
+				_ = fcandidate // todo: I have no idea what is under fcandidate, but it's a large number
 			}
 
 			gencandidates := time.Now()
@@ -423,10 +424,10 @@ var sealBenchCmd = &cli.Command{
 			epost2 := time.Now()
 
 			pvi1 := abi.WinningPoStVerifyInfo{
-				Randomness:      abi.PoStRandomness(challenge[:]),
-				Proofs:          proof1,
+				Randomness:        abi.PoStRandomness(challenge[:]),
+				Proofs:            proof1,
 				ChallengedSectors: candidates,
-				Prover:          mid,
+				Prover:            mid,
 			}
 			ok, err := ffiwrapper.ProofVerifier.VerifyWinningPoSt(context.TODO(), pvi1)
 			if err != nil {
@@ -439,10 +440,10 @@ var sealBenchCmd = &cli.Command{
 			verifypost1 := time.Now()
 
 			pvi2 := abi.WinningPoStVerifyInfo{
-				Randomness:      abi.PoStRandomness(challenge[:]),
-				Proofs:          proof2,
+				Randomness:        abi.PoStRandomness(challenge[:]),
+				Proofs:            proof2,
 				ChallengedSectors: candidates,
-				Prover:          mid,
+				Prover:            mid,
 			}
 
 			ok, err = ffiwrapper.ProofVerifier.VerifyWinningPoSt(context.TODO(), pvi2)
@@ -534,7 +535,7 @@ var proveCmd = &cli.Command{
 			return err
 		}
 
-		_, spt, err := ffiwrapper.ProofTypeFromSectorSize(abi.SectorSize(c2in.SectorSize))
+		_, spt, err := ffiwrapper.SealProofTypeFromSectorSize(abi.SectorSize(c2in.SectorSize))
 		if err != nil {
 			return err
 		}
diff --git a/cmd/lotus-seal-worker/main.go b/cmd/lotus-seal-worker/main.go
index effb5900f..fdbb450c4 100644
--- a/cmd/lotus-seal-worker/main.go
+++ b/cmd/lotus-seal-worker/main.go
@@ -242,7 +242,7 @@ var runCmd = &cli.Command{
 		}
 
 		// Setup remote sector store
-		_, spt, err := ffiwrapper.ProofTypeFromSectorSize(ssize)
+		_, spt, err := ffiwrapper.SealProofTypeFromSectorSize(ssize)
 		if err != nil {
 			return xerrors.Errorf("getting proof type: %w", err)
 		}
diff --git a/cmd/lotus-seed/main.go b/cmd/lotus-seed/main.go
index 3b544d010..97bf57ac0 100644
--- a/cmd/lotus-seed/main.go
+++ b/cmd/lotus-seed/main.go
@@ -120,7 +120,7 @@ var preSealCmd = &cli.Command{
 		}
 		sectorSize := abi.SectorSize(sectorSizeInt)
 
-		rp, _, err := ffiwrapper.ProofTypeFromSectorSize(sectorSize)
+		rp, _, err := ffiwrapper.SealProofTypeFromSectorSize(sectorSize)
 		if err != nil {
 			return err
 		}
diff --git a/cmd/lotus-storage-miner/init.go b/cmd/lotus-storage-miner/init.go
index 535abf000..dbed16453 100644
--- a/cmd/lotus-storage-miner/init.go
+++ b/cmd/lotus-storage-miner/init.go
@@ -413,7 +413,7 @@ func storageMinerInit(ctx context.Context, cctx *cli.Context, api lapi.FullNode,
 				return err
 			}
 
-			ppt, spt, err := ffiwrapper.ProofTypeFromSectorSize(ssize)
+			ppt, spt, err := ffiwrapper.SealProofTypeFromSectorSize(ssize)
 			if err != nil {
 				return err
 			}
diff --git a/go.sum b/go.sum
index d0cab0e9f..bc0430e80 100644
--- a/go.sum
+++ b/go.sum
@@ -130,7 +130,6 @@ github.com/filecoin-project/chain-validation v0.0.3 h1:luT/8kJ0WdMIqQ9Bm31W4JkuY
 github.com/filecoin-project/chain-validation v0.0.3/go.mod h1:NCEGFjcWRjb8akWFSOXvU6n2efkWIqAeOKU6o5WBGQw=
 github.com/filecoin-project/chain-validation v0.0.6-0.20200331143132-15970e639ac2 h1:kRaCruOKzFy5mE5lwPecKD5aztzmazMQDot38NgT6E0=
 github.com/filecoin-project/chain-validation v0.0.6-0.20200331143132-15970e639ac2/go.mod h1:mXiAviXMZ2WVGmWNtjGr0JPMpNCNsPU774DawKZCzzM=
-github.com/filecoin-project/go-address v0.0.0-20191219011437-af739c490b4f/go.mod h1:rCbpXPva2NKF9/J4X6sr7hbKBgQCxyFtRj7KOZqoIms=
 github.com/filecoin-project/go-address v0.0.0-20200107215422-da8eea2842b5/go.mod h1:SAOwJoakQ8EPjwNIsiakIQKsoKdkcbx8U3IapgCg9R0=
 github.com/filecoin-project/go-address v0.0.2-0.20200218010043-eb9bb40ed5be h1:TooKBwR/g8jG0hZ3lqe9S5sy2vTUcLOZLlz3M5wGn2E=
 github.com/filecoin-project/go-address v0.0.2-0.20200218010043-eb9bb40ed5be/go.mod h1:SAOwJoakQ8EPjwNIsiakIQKsoKdkcbx8U3IapgCg9R0=
@@ -152,9 +151,6 @@ github.com/filecoin-project/go-data-transfer v0.0.0-20200408061858-82c58b423ca6/
 github.com/filecoin-project/go-data-transfer v0.0.0-20200408061858-82c58b423ca6/go.mod h1:7b5/sG9Jj33aWqft8XsH8yIdxZBACqS5tx9hv4uj2Ck=
 github.com/filecoin-project/go-fil-commcid v0.0.0-20200208005934-2b8bd03caca5 h1:yvQJCW9mmi9zy+51xA01Ea2X7/dL7r8eKDPuGUjRmbo=
 github.com/filecoin-project/go-fil-commcid v0.0.0-20200208005934-2b8bd03caca5/go.mod h1:JbkIgFF/Z9BDlvrJO1FuKkaWsH673/UdFaiVS6uIHlA=
-github.com/filecoin-project/go-fil-markets v0.0.0-20200114015428-74d100f305f8/go.mod h1:c8NTjvFVy1Ud02mmGDjOiMeawY2t6ALfrrdvAB01FQc=
-github.com/filecoin-project/go-fil-markets v0.0.0-20200408062434-d92f329a6428 h1:y8P10ZwfmsKMVHrqcU1L8Bgj2q42O6LzaySI+XaogXE=
-github.com/filecoin-project/go-fil-markets v0.0.0-20200408062434-d92f329a6428/go.mod h1:NmuTIqaivdyUzmvHOUCsTDGEtNjOZQwC1cgW3W/02m4=
 github.com/filecoin-project/go-padreader v0.0.0-20200210211231-548257017ca6 h1:92PET+sx1Hb4W/8CgFwGuxaKbttwY+UNspYZTvXY0vs=
 github.com/filecoin-project/go-padreader v0.0.0-20200210211231-548257017ca6/go.mod h1:0HgYnrkeSU4lu1p+LEOeDpFsNBssa0OGGriWdA4hvaE=
 github.com/filecoin-project/go-paramfetch v0.0.0-20200102181131-b20d579f2878/go.mod h1:40kI2Gv16mwcRsHptI3OAV4nlOEU7wVDc4RgMylNFjU=
@@ -167,18 +163,11 @@ github.com/filecoin-project/go-statemachine v0.0.0-20200226041606-2074af6d51d9/g
 github.com/filecoin-project/go-statestore v0.1.0 h1:t56reH59843TwXHkMcwyuayStBIiWBRilQjQ+5IiwdQ=
 github.com/filecoin-project/go-statestore v0.1.0/go.mod h1:LFc9hD+fRxPqiHiaqUEZOinUJB4WARkRfNl10O7kTnI=
 github.com/filecoin-project/lotus v0.2.10/go.mod h1:om5PQA9ZT0lf16qI7Fz/ZGLn4LDCMqPC8ntZA9uncRE=
-github.com/filecoin-project/sector-storage v0.0.0-20200406195014-a6d093838576 h1:MzBqbddYp/vdFOC3WNu3tSWfLFwHUP8Orcx2CxjRPyo=
-github.com/filecoin-project/sector-storage v0.0.0-20200406195014-a6d093838576/go.mod h1:yT100eeKHGO9xU3rfkeM2/8NcBktxe2nBkDT4WmD1lA=
 github.com/filecoin-project/specs-actors v0.0.0-20200210130641-2d1fbd8672cf/go.mod h1:xtDZUB6pe4Pksa/bAJbJ693OilaC5Wbot9jMhLm3cZA=
-github.com/filecoin-project/specs-actors v0.0.0-20200220011005-b2a2fbf40362/go.mod h1:xtDZUB6pe4Pksa/bAJbJ693OilaC5Wbot9jMhLm3cZA=
-github.com/filecoin-project/specs-actors v0.0.0-20200226200336-94c9b92b2775/go.mod h1:0HAWYrvajFHDgRaKbF0rl+IybVLZL5z4gQ8koCMPhoU=
-github.com/filecoin-project/specs-actors v0.0.0-20200302223606-0eaf97b10aaf/go.mod h1:0HAWYrvajFHDgRaKbF0rl+IybVLZL5z4gQ8koCMPhoU=
 github.com/filecoin-project/specs-actors v0.0.0-20200324235424-aef9b20a9fb1 h1:IL6A1yAamz0HtLQEdZS57hnRZHPL11VIrQxMZ1Nn5hI=
 github.com/filecoin-project/specs-actors v0.0.0-20200324235424-aef9b20a9fb1/go.mod h1:5WngRgTN5Eo4+0SjCBqLzEr2l6Mj45DrP2606gBhqI0=
 github.com/filecoin-project/specs-actors v0.0.0-20200409043918-e569f4a2f504 h1:mwuAaqxKThl70+7FkGdFKVLdwaQZQ8XmscKdhSBBtnc=
 github.com/filecoin-project/specs-actors v0.0.0-20200409043918-e569f4a2f504/go.mod h1:mdJraXq5vMy0+/FqVQIrnNlpQ/Em6zeu06G/ltQ0/lA=
-github.com/filecoin-project/specs-storage v0.0.0-20200317225704-7420bc655c38 h1:ky+rfX3bG1TjOBLn14V674q+iwZpalyKzZxGRNzA11I=
-github.com/filecoin-project/specs-storage v0.0.0-20200317225704-7420bc655c38/go.mod h1:dUmzHS7izOD6HW3/JpzFrjxnptxbsHXBlO8puK2UzBk=
 github.com/filecoin-project/storage-fsm v0.0.0-20200407163248-25993479b13f h1:WPA4Lj1PLBVKFe8nKs8UdJ7fj4luFKR62eRDpVNo9CU=
 github.com/filecoin-project/storage-fsm v0.0.0-20200407163248-25993479b13f/go.mod h1:t3dyEJiCkdQjo0h75mir3x5a0vSPHi9woQO7UkkZpFg=
 github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
@@ -288,9 +277,7 @@ github.com/ipfs/go-blockservice v0.1.3-0.20190908200855-f22eea50656c/go.mod h1:t
 github.com/ipfs/go-blockservice v0.1.3 h1:9XgsPMwwWJSC9uVr2pMDsW2qFTBSkxpGMhmna8mIjPM=
 github.com/ipfs/go-blockservice v0.1.3/go.mod h1:OTZhFpkgY48kNzbgyvcexW9cHrpjBYIjSR0KoDOFOLU=
 github.com/ipfs/go-blockservice v0.1.3/go.mod h1:OTZhFpkgY48kNzbgyvcexW9cHrpjBYIjSR0KoDOFOLU=
-github.com/ipfs/go-car v0.0.3-0.20191203022317-23b0a85fd1b1/go.mod h1:rmd887mJxQRDfndfDEY3Liyx8gQVyfFFRSHdsnDSAlk=
 github.com/ipfs/go-car v0.0.3-0.20200121013634-f188c0e24291/go.mod h1:AG6sBpd2PWMccpAG7XLFBBQ/4rfBEtzUNeO2GSMesYk=
-github.com/ipfs/go-car v0.0.3-0.20200131220434-3f68f6ebd093/go.mod h1:rEkw0S1sHd5kHL3rUSGEhwNanYqTwwNhjtpp0rwjrr4=
 github.com/ipfs/go-car v0.0.3-0.20200304012825-b6769248bfef h1:Zn2PZSkX8Go+SZpQmjVKNrkcgbNuIxUC/3MOQRDTIVw=
 github.com/ipfs/go-car v0.0.3-0.20200304012825-b6769248bfef/go.mod h1:7BMxYRi5cbR/GJ1A8mYSHvMLXLkHgYdrJ6VlNGobd0o=
 github.com/ipfs/go-cid v0.0.1/go.mod h1:GHWU/WuQdMPmIosc4Yn1bcCT7dSeX4lBafM7iqUPQvM=
@@ -814,7 +801,6 @@ github.com/prometheus/procfs v0.0.0-20190117184657-bf6a532e95b1/go.mod h1:c3At6R
 github.com/prometheus/procfs v0.0.0-20190425082905-87a4384529e0 h1:c8R11WC8m7KNMkTv/0+Be8vvwo4I3/Ut9AC2FW8fX3U=
 github.com/prometheus/procfs v0.0.0-20190425082905-87a4384529e0/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/rcrowley/go-metrics v0.0.0-20181016184325-3113b8401b8a/go.mod h1:bCqnVzQkZxMG4s8nGwiZ5l3QUCyqpo9Y+/ZMZ9VjZe4=
-github.com/remyoudompheng/bigfft v0.0.0-20190728182440-6a916e37a237/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/russross/blackfriday v1.5.2 h1:HyvC0ARfnZBqnXwABFeSZHpKvJHJJfPz81GNueLj0oo=
@@ -861,7 +847,6 @@ github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UV
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/syndtr/goleveldb v1.0.0/go.mod h1:ZVVdQEZoIme9iO1Ch2Jdy24qqXrMMOU6lpPAyBWyWuQ=
-github.com/tj/go-spin v1.1.0/go.mod h1:Mg1mzmePZm4dva8Qz60H2lHwmJ2loum4VIrLgVnKwh4=
 github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
 github.com/urfave/cli v1.20.0 h1:fDqGv3UG/4jbVl/QkFwEdddtEDjh/5Ov6X+0B/3bPaw=
 github.com/urfave/cli v1.20.0/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=
@@ -915,8 +900,6 @@ github.com/whyrusleeping/timecache v0.0.0-20160911033111-cfcb2f1abfee/go.mod h1:
 github.com/whyrusleeping/yamux v1.1.5/go.mod h1:E8LnQQ8HKx5KD29HZFUwM1PxCOdPRzGwur1mcYhXcD8=
 github.com/x-cray/logrus-prefixed-formatter v0.5.2 h1:00txxvfBM9muc0jiLIEAkAcIMJzfthRT6usrui8uGmg=
 github.com/x-cray/logrus-prefixed-formatter v0.5.2/go.mod h1:2duySbKsL6M18s5GU7VPsoEPHyzalCE06qoARUCeBBE=
-github.com/xlab/c-for-go v0.0.0-20200116014644-76fdc4a01753/go.mod h1:IW51aYj15pzGQpgS/r4N84qI+g2fNAiTjYK5l8Gz1w0=
-github.com/xlab/pkgconfig v0.0.0-20170226114623-cea12a0fd245/go.mod h1:C+diUUz7pxhNY6KAoLgrTYARGWnt82zWTylZlxT92vk=
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 go.dedis.ch/fixbuf v1.0.3/go.mod h1:yzJMt34Wa5xD37V5RTdmp38cz3QhMagdGoem9anUalw=
@@ -1151,8 +1134,3 @@ howett.net/plist v0.0.0-20181124034731-591f970eefbb h1:jhnBjNi9UFpfpl8YZhA9CrOqp
 howett.net/plist v0.0.0-20181124034731-591f970eefbb/go.mod h1:vMygbs4qMhSZSc4lCUl2OEE+rDiIIJAIdR4m7MiMcm0=
 launchpad.net/gocheck v0.0.0-20140225173054-000000000087 h1:Izowp2XBH6Ya6rv+hqbceQyw/gSGoXfH/UPoTGduL54=
 launchpad.net/gocheck v0.0.0-20140225173054-000000000087/go.mod h1:hj7XX3B/0A+80Vse0e+BUHsHMTEhd0O4cpUHr/e/BUM=
-modernc.org/cc v1.0.0/go.mod h1:1Sk4//wdnYJiUIxnW8ddKpaOJCF37yAdqYnkxUpaYxw=
-modernc.org/golex v1.0.0/go.mod h1:b/QX9oBD/LhixY6NDh+IdGv17hgB+51fET1i2kPSmvk=
-modernc.org/mathutil v1.1.0/go.mod h1:Jip3gBlE32vJMsD4RJ5qzniC0pvRnCxrlwmKPZrrLXI=
-modernc.org/strutil v1.1.0/go.mod h1:lstksw84oURvj9y3tn8lGvRxyRC1S2+g5uuIzNfIOBs=
-modernc.org/xc v1.0.0/go.mod h1:mRNCo0bvLjGhHO9WsyuKVU4q0ceiDDDoEeWDJHrNx8I=
diff --git a/miner/miner.go b/miner/miner.go
index c77da1bd9..2d4131794 100644
--- a/miner/miner.go
+++ b/miner/miner.go
@@ -27,7 +27,7 @@ var log = logging.Logger("miner")
 
 type waitFunc func(ctx context.Context, baseTime uint64) error
 
-func NewMiner(api api.FullNode, epp gen.ElectionPoStProver, beacon beacon.RandomBeacon) *Miner {
+func NewMiner(api api.FullNode, epp gen.WinningPoStProver, beacon beacon.RandomBeacon) *Miner {
 	arc, err := lru.NewARC(10000)
 	if err != nil {
 		panic(err)
@@ -51,7 +51,7 @@ func NewMiner(api api.FullNode, epp gen.ElectionPoStProver, beacon beacon.Random
 type Miner struct {
 	api api.FullNode
 
-	epp    gen.ElectionPoStProver
+	epp    gen.WinningPoStProver
 	beacon beacon.RandomBeacon
 
 	lk        sync.Mutex
diff --git a/miner/testminer.go b/miner/testminer.go
index 7b7d6f476..67901ad53 100644
--- a/miner/testminer.go
+++ b/miner/testminer.go
@@ -10,8 +10,8 @@ import (
 	lru "github.com/hashicorp/golang-lru"
 )
 
-func NewTestMiner(nextCh <-chan struct{}, addr address.Address) func(api.FullNode, gen.ElectionPoStProver) *Miner {
-	return func(api api.FullNode, epp gen.ElectionPoStProver) *Miner {
+func NewTestMiner(nextCh <-chan struct{}, addr address.Address) func(api.FullNode, gen.WinningPoStProver) *Miner {
+	return func(api api.FullNode, epp gen.WinningPoStProver) *Miner {
 		arc, err := lru.NewARC(10000)
 		if err != nil {
 			panic(err)
diff --git a/node/builder.go b/node/builder.go
index 4b799fcf7..77ebb921a 100644
--- a/node/builder.go
+++ b/node/builder.go
@@ -298,7 +298,7 @@ func Online() Option {
 			Override(HandleRetrievalKey, modules.HandleRetrieval),
 			Override(GetParamsKey, modules.GetParams),
 			Override(HandleDealsKey, modules.HandleDeals),
-			Override(new(gen.ElectionPoStProver), storage.NewElectionPoStProver),
+			Override(new(gen.WinningPoStProver), storage.NewElectionPoStProver),
 			Override(new(*miner.Miner), modules.SetupBlockProducer),
 		),
 	)
diff --git a/node/impl/client/client.go b/node/impl/client/client.go
index c912d93fb..b59fcdf1e 100644
--- a/node/impl/client/client.go
+++ b/node/impl/client/client.go
@@ -85,7 +85,7 @@ func (a *API) ClientStartDeal(ctx context.Context, params *api.StartDealParams)
 		return nil, xerrors.Errorf("failed checking miners sector size: %w", err)
 	}
 
-	rt, _, err := ffiwrapper.ProofTypeFromSectorSize(ssize)
+	rt, _, err := ffiwrapper.SealProofTypeFromSectorSize(ssize)
 	if err != nil {
 		return nil, xerrors.Errorf("bad sector size: %w", err)
 	}
diff --git a/node/modules/storageminer.go b/node/modules/storageminer.go
index c705268c0..5221e129f 100644
--- a/node/modules/storageminer.go
+++ b/node/modules/storageminer.go
@@ -96,14 +96,13 @@ func ProofsConfig(maddr dtypes.MinerAddress, fnapi lapi.FullNode) (*ffiwrapper.C
 		return nil, err
 	}
 
-	ppt, spt, err := ffiwrapper.ProofTypeFromSectorSize(ssize)
+	_, spt, err := ffiwrapper.SealProofTypeFromSectorSize(ssize)
 	if err != nil {
 		return nil, xerrors.Errorf("bad sector size: %w", err)
 	}
 
 	sb := &ffiwrapper.Config{
 		SealProofType: spt,
-		PoStProofType: ppt,
 	}
 
 	return sb, nil
@@ -136,7 +135,7 @@ func StorageMiner(mctx helpers.MetricsCtx, lc fx.Lifecycle, api lapi.FullNode, h
 		return nil, err
 	}
 
-	ppt, _, err := ffiwrapper.ProofTypeFromSectorSize(sealer.SectorSize()) // TODO: this changes
+	ppt, _, err := ffiwrapper.SealProofTypeFromSectorSize(sealer.SectorSize()) // TODO: this changes
 	if err != nil {
 		return nil, xerrors.Errorf("bad sector size: %w", err)
 	}
@@ -256,7 +255,7 @@ func StagingGraphsync(mctx helpers.MetricsCtx, lc fx.Lifecycle, ibs dtypes.Stagi
 	return gs
 }
 
-func SetupBlockProducer(lc fx.Lifecycle, ds dtypes.MetadataDS, api lapi.FullNode, epp gen.ElectionPoStProver, beacon beacon.RandomBeacon) (*miner.Miner, error) {
+func SetupBlockProducer(lc fx.Lifecycle, ds dtypes.MetadataDS, api lapi.FullNode, epp gen.WinningPoStProver, beacon beacon.RandomBeacon) (*miner.Miner, error) {
 	minerAddr, err := minerAddrFromDS(ds)
 	if err != nil {
 		return nil, err
@@ -320,7 +319,7 @@ func StorageProvider(ctx helpers.MetricsCtx, fapi lapi.FullNode, h host.Host, ds
 		return nil, err
 	}
 
-	rt, _, err := ffiwrapper.ProofTypeFromSectorSize(ssize)
+	rt, _, err := ffiwrapper.SealProofTypeFromSectorSize(ssize)
 	if err != nil {
 		return nil, err
 	}
diff --git a/storage/miner.go b/storage/miner.go
index 6d0d6f569..61b2ecc16 100644
--- a/storage/miner.go
+++ b/storage/miner.go
@@ -125,22 +125,22 @@ func (m *Miner) runPreflightChecks(ctx context.Context) error {
 	return nil
 }
 
-type StorageEpp struct {
-	prover storage.Prover
-	miner  abi.ActorID
+type StorageWpp struct {
+	prover  storage.Prover
+	miner   abi.ActorID
+	winnRpt abi.RegisteredProof
 }
 
-func NewElectionPoStProver(sb storage.Prover, miner dtypes.MinerID) *StorageEpp {
-	return &StorageEpp{sb, abi.ActorID(miner)}
+func NewElectionPoStProver(sb storage.Prover, miner dtypes.MinerID, winnRpt abi.RegisteredProof) *StorageWpp {
+	return &StorageWpp{sb, abi.ActorID(miner), winnRpt}
 }
 
-var _ gen.ElectionPoStProver = (*StorageEpp)(nil)
+var _ gen.WinningPoStProver = (*StorageWpp)(nil)
 
-func (epp *StorageEpp) GenerateCandidates(ctx context.Context, ssi []abi.SectorInfo, rand abi.PoStRandomness) ([]storage.PoStCandidateWithTicket, error) {
+func (wpp *StorageWpp) GenerateCandidates(ctx context.Context, randomness abi.PoStRandomness, eligibleSectorCount uint64) ([]uint64, error) {
 	start := time.Now()
-	var faults []abi.SectorNumber // TODO
 
-	cds, err := epp.prover.GenerateEPostCandidates(ctx, epp.miner, ssi, rand, faults)
+	cds, err := wpp.prover.GenerateWinningPoStSectorChallenge(ctx, wpp.winnRpt, wpp.miner, randomness, eligibleSectorCount)
 	if err != nil {
 		return nil, xerrors.Errorf("failed to generate candidates: %w", err)
 	}
@@ -148,19 +148,14 @@ func (epp *StorageEpp) GenerateCandidates(ctx context.Context, ssi []abi.SectorI
 	return cds, nil
 }
 
-func (epp *StorageEpp) ComputeProof(ctx context.Context, ssi []abi.SectorInfo, rand []byte, winners []storage.PoStCandidateWithTicket) ([]abi.PoStProof, error) {
+func (wpp *StorageWpp) ComputeProof(ctx context.Context, ssi []abi.SectorInfo, rand []byte) ([]abi.PoStProof, error) {
 	if build.InsecurePoStValidation {
 		log.Warn("Generating fake EPost proof! You should only see this while running tests!")
 		return []abi.PoStProof{{ProofBytes: []byte("valid proof")}}, nil
 	}
 
-	owins := make([]abi.PoStCandidate, 0, len(winners))
-	for _, w := range winners {
-		owins = append(owins, w.Candidate)
-	}
-
 	start := time.Now()
-	proof, err := epp.prover.ComputeElectionPoSt(ctx, epp.miner, ssi, rand, owins)
+	proof, err := wpp.prover.GenerateWinningPoSt(ctx, wpp.miner, ssi, rand)
 	if err != nil {
 		return nil, err
 	}
diff --git a/storage/mockstorage/preseal.go b/storage/mockstorage/preseal.go
index 4cc6be178..1a2c01e8b 100644
--- a/storage/mockstorage/preseal.go
+++ b/storage/mockstorage/preseal.go
@@ -31,7 +31,7 @@ func PreSeal(ssize abi.SectorSize, maddr address.Address, sectors int) (*genesis
 		Sectors:       make([]*genesis.PreSeal, sectors),
 	}
 
-	_, st, err := ffiwrapper.ProofTypeFromSectorSize(ssize)
+	_, st, err := ffiwrapper.SealProofTypeFromSectorSize(ssize)
 	if err != nil {
 		return nil, nil, err
 	}
diff --git a/storage/wdpost_run.go b/storage/wdpost_run.go
index 8bf47d081..4aaecf33f 100644
--- a/storage/wdpost_run.go
+++ b/storage/wdpost_run.go
@@ -39,7 +39,7 @@ func (s *WindowPoStScheduler) doPost(ctx context.Context, deadline *Deadline, ts
 		ctx, span := trace.StartSpan(ctx, "WindowPoStScheduler.doPost")
 		defer span.End()
 
-		proof, err := s.runPost(ctx, deadline, ts)
+		proof, err := s.runPost(ctx, *deadline, ts)
 		if err != nil {
 			log.Errorf("runPost failed: %+v", err)
 			s.failPost(deadline)
@@ -144,7 +144,7 @@ func (s *WindowPoStScheduler) checkFaults(ctx context.Context, ssi []abi.SectorN
 	return faultIDs, nil
 }
 
-func (s *WindowPoStScheduler) runPost(ctx context.Context, deadline Deadline, ts *types.TipSet) (*abi.OnChainPoStVerifyInfo, error) {
+func (s *WindowPoStScheduler) runPost(ctx context.Context, deadline Deadline, ts *types.TipSet) (*abi.OnChainWindowPoStVerifyInfo, error) {
 	ctx, span := trace.StartSpan(ctx, "storage.runPost")
 	defer span.End()
 
@@ -199,38 +199,21 @@ func (s *WindowPoStScheduler) runPost(ctx context.Context, deadline Deadline, ts
 		return nil, err
 	}
 
-	postOut, err := s.prover.GenerateFallbackPoSt(ctx, abi.ActorID(mid), ssi, abi.PoStRandomness(rand), faults)
+	// TODO: Faults!
+	postOut, err := s.prover.GenerateWindowPoSt(ctx, abi.ActorID(mid), ssi, abi.PoStRandomness(rand))
 	if err != nil {
 		return nil, xerrors.Errorf("running post failed: %w", err)
 	}
 
-	if len(postOut.PoStInputs) == 0 {
-		return nil, xerrors.Errorf("received zero candidates back from generate fallback post")
+	if len(postOut) == 0 {
+		return nil, xerrors.Errorf("received proofs back from generate window post")
 	}
 
-	// TODO: until we figure out how fallback post is really supposed to work,
-	// let's just pass a single candidate...
-	scandidates := postOut.PoStInputs[:1]
-	proof := postOut.Proof[:1]
-
 	elapsed := time.Since(tsStart)
-	log.Infow("submitting PoSt", "pLen", len(proof), "elapsed", elapsed)
+	log.Infow("submitting PoSt", "elapsed", elapsed)
 
-	candidates := make([]abi.PoStCandidate, len(scandidates))
-	for i, sc := range scandidates {
-		part := make([]byte, 32)
-		copy(part, sc.Candidate.PartialTicket[:])
-		candidates[i] = abi.PoStCandidate{
-			RegisteredProof: s.proofType,
-			PartialTicket:   part,
-			SectorID:        sc.Candidate.SectorID,
-			ChallengeIndex:  sc.Candidate.ChallengeIndex,
-		}
-	}
-
-	return &abi.OnChainPoStVerifyInfo{
-		Proofs:     proof,
-		Candidates: candidates,
+	return &abi.OnChainWindowPoStVerifyInfo{
+		Proofs: postOut,
 	}, nil
 }
 
@@ -252,7 +235,7 @@ func (s *WindowPoStScheduler) sortedSectorInfo(ctx context.Context, partitions [
 	return sbsi, nil
 }
 
-func (s *WindowPoStScheduler) submitPost(ctx context.Context, proof *abi.OnChainPoStVerifyInfo) error {
+func (s *WindowPoStScheduler) submitPost(ctx context.Context, proof *abi.OnChainWindowPoStVerifyInfo) error {
 	ctx, span := trace.StartSpan(ctx, "storage.commitPost")
 	defer span.End()
 
diff --git a/storage/wdpost_sched.go b/storage/wdpost_sched.go
index 252f0c80e..406c90c77 100644
--- a/storage/wdpost_sched.go
+++ b/storage/wdpost_sched.go
@@ -30,7 +30,7 @@ type WindowPoStScheduler struct {
 
 	// if a post is in progress, this indicates for which ElectionPeriodStart
 	activeDeadline *Deadline
-	abort     context.CancelFunc
+	abort          context.CancelFunc
 
 	//failed abi.ChainEpoch // eps
 	//failLk sync.Mutex
@@ -40,14 +40,13 @@ func NewWindowedPoStScheduler(api storageMinerApi, sb storage.Prover, actor addr
 	return &WindowPoStScheduler{api: api, prover: sb, actor: actor, worker: worker, proofType: rt}
 }
 
-const ProvingDeadlineEpochs = (30*60) / build.BlockDelay
+const ProvingDeadlineEpochs = (30 * 60) / build.BlockDelay
 const ProvingPeriodDeadlines = 48
 const ProvingPeriodEpochs = ProvingDeadlineEpochs * ProvingDeadlineEpochs
 
 type Deadline struct {
 	// ID
 	start abi.ChainEpoch
-
 }
 
 func (Deadline) Equals(other Deadline) bool {
@@ -183,8 +182,6 @@ func (s *WindowPoStScheduler) update(ctx context.Context, new *types.TipSet) err
 	}
 	s.failLk.Unlock()*/
 
-
-
 	s.abortActivePoSt()
 
 	if newDeadline != nil {