diff --git a/revocation/crl/fetcher.go b/revocation/crl/fetcher.go
index f0baacc4..44ba4dd1 100644
--- a/revocation/crl/fetcher.go
+++ b/revocation/crl/fetcher.go
@@ -18,6 +18,7 @@ package crl
 import (
 	"context"
 	"crypto/x509"
+	"crypto/x509/pkix"
 	"encoding/asn1"
 	"errors"
 	"fmt"
@@ -25,6 +26,9 @@ import (
 	"net/http"
 	"net/url"
 	"time"
+
+	"golang.org/x/crypto/cryptobyte"
+	cryptobyte_asn1 "golang.org/x/crypto/cryptobyte/asn1"
 )
 
 // oidFreshestCRL is the object identifier for the distribution point
@@ -44,6 +48,15 @@ type Fetcher interface {
 	Fetch(ctx context.Context, url string) (*Bundle, error)
 }
 
+// FetcherWithCertificateExtensions is an interface that specifies methods used
+// for fetching CRL from the given URL with certificate extensions to identify
+// the Freshest CRL extension (Delta CRL) from certificate.
+type FetcherWithCertificateExtensions interface {
+	// FetchWithCertificateExtensions retrieves the CRL from the given URL with
+	// certificate extensions.
+	FetchWithCertificateExtensions(ctx context.Context, url string, certificateExtensions *[]pkix.Extension) (*Bundle, error)
+}
+
 // HTTPFetcher is a Fetcher implementation that fetches CRL from the given URL
 type HTTPFetcher struct {
 	// Cache stores fetched CRLs and reuses them until the CRL reaches the
@@ -77,6 +90,10 @@ func NewHTTPFetcher(httpClient *http.Client) (*HTTPFetcher, error) {
 // (e.g. cache miss), it will download the CRL from the URL and store it to the
 // cache.
 func (f *HTTPFetcher) Fetch(ctx context.Context, url string) (*Bundle, error) {
+	return f.FetchWithCertificateExtensions(ctx, url, nil)
+}
+
+func (f *HTTPFetcher) FetchWithCertificateExtensions(ctx context.Context, url string, certificateExtensions *[]pkix.Extension) (*Bundle, error) {
 	if url == "" {
 		return nil, errors.New("CRL URL cannot be empty")
 	}
@@ -84,9 +101,9 @@ func (f *HTTPFetcher) Fetch(ctx context.Context, url string) (*Bundle, error) {
 	if f.Cache != nil {
 		bundle, err := f.Cache.Get(ctx, url)
 		if err == nil {
-			// check expiry
-			nextUpdate := bundle.BaseCRL.NextUpdate
-			if !nextUpdate.IsZero() && !time.Now().After(nextUpdate) {
+			// check expiry of base CRL and delta CRL
+			if (bundle.BaseCRL != nil && isEffective(bundle.BaseCRL)) &&
+				(bundle.DeltaCRL == nil || isEffective(bundle.DeltaCRL)) {
 				return bundle, nil
 			}
 		} else if !errors.Is(err, ErrCacheMiss) && !f.DiscardCacheError {
@@ -94,7 +111,7 @@ func (f *HTTPFetcher) Fetch(ctx context.Context, url string) (*Bundle, error) {
 		}
 	}
 
-	bundle, err := f.fetch(ctx, url)
+	bundle, err := f.fetch(ctx, url, certificateExtensions)
 	if err != nil {
 		return nil, fmt.Errorf("failed to retrieve CRL: %w", err)
 	}
@@ -109,27 +126,113 @@ func (f *HTTPFetcher) Fetch(ctx context.Context, url string) (*Bundle, error) {
 	return bundle, nil
 }
 
+// isEffective checks if the CRL is effective by checking the NextUpdate time.
+func isEffective(crl *x509.RevocationList) bool {
+	return !crl.NextUpdate.IsZero() && !time.Now().After(crl.NextUpdate)
+}
+
 // fetch downloads the CRL from the given URL.
-func (f *HTTPFetcher) fetch(ctx context.Context, url string) (*Bundle, error) {
+func (f *HTTPFetcher) fetch(ctx context.Context, url string, certificateExtensions *[]pkix.Extension) (*Bundle, error) {
 	// fetch base CRL
 	base, err := fetchCRL(ctx, url, f.httpClient)
 	if err != nil {
 		return nil, err
 	}
 
-	// check delta CRL
-	// TODO: support delta CRL https://github.com/notaryproject/notation-core-go/issues/228
-	for _, ext := range base.Extensions {
-		if ext.Id.Equal(oidFreshestCRL) {
-			return nil, errors.New("delta CRL is not supported")
+	// fetch delta CRL from CRL extension
+	deltaCRL, err := f.processDeltaCRL(&base.Extensions)
+	if err != nil {
+		return nil, err
+	}
+	if certificateExtensions != nil && deltaCRL == nil {
+		// fallback to fetch delta CRL from certificate extension
+		deltaCRL, err = f.processDeltaCRL(certificateExtensions)
+		if err != nil {
+			return nil, err
 		}
 	}
 
 	return &Bundle{
-		BaseCRL: base,
+		BaseCRL:  base,
+		DeltaCRL: deltaCRL,
 	}, nil
 }
 
+func (f *HTTPFetcher) processDeltaCRL(extensions *[]pkix.Extension) (*x509.RevocationList, error) {
+	for _, ext := range *extensions {
+		if ext.Id.Equal(oidFreshestCRL) {
+			cdp, err := parseFreshestCRL(ext)
+			if err != nil {
+				return nil, fmt.Errorf("failed to parse Freshest CRL extension: %w", err)
+			}
+			if len(cdp) == 0 {
+				return nil, nil
+			}
+			if len(cdp) > 1 {
+				// to simplify the implementation, we only support one
+				// Freshest CRL URL for now which is the common case
+				return nil, errors.New("multiple Freshest CRL distribution points are not supported")
+			}
+			return fetchCRL(context.Background(), cdp[0], f.httpClient)
+		}
+	}
+	return nil, nil
+}
+
+// parseFreshestCRL parses the Freshest CRL extension and returns the CRL URLs
+func parseFreshestCRL(ext pkix.Extension) ([]string, error) {
+	var cdp []string
+	// RFC 5280, 4.2.1.15
+	//    id-ce-freshestCRL OBJECT IDENTIFIER ::=  { id-ce 46 }
+	//
+	//    FreshestCRL ::= CRLDistributionPoints
+	//
+	// RFC 5280, 4.2.1.13
+	//
+	// CRLDistributionPoints ::= SEQUENCE SIZE (1..MAX) OF DistributionPoint
+	//
+	// DistributionPoint ::= SEQUENCE {
+	//     distributionPoint       [0]     DistributionPointName OPTIONAL,
+	//     reasons                 [1]     ReasonFlags OPTIONAL,
+	//     cRLIssuer               [2]     GeneralNames OPTIONAL }
+	//
+	// DistributionPointName ::= CHOICE {
+	//     fullName                [0]     GeneralNames,
+	//     nameRelativeToCRLIssuer [1]     RelativeDistinguishedName }
+	val := cryptobyte.String(ext.Value)
+	if !val.ReadASN1(&val, cryptobyte_asn1.SEQUENCE) {
+		return nil, errors.New("x509: invalid CRL distribution points")
+	}
+	for !val.Empty() {
+		var dpDER cryptobyte.String
+		if !val.ReadASN1(&dpDER, cryptobyte_asn1.SEQUENCE) {
+			return nil, errors.New("x509: invalid CRL distribution point")
+		}
+		var dpNameDER cryptobyte.String
+		var dpNamePresent bool
+		if !dpDER.ReadOptionalASN1(&dpNameDER, &dpNamePresent, cryptobyte_asn1.Tag(0).Constructed().ContextSpecific()) {
+			return nil, errors.New("x509: invalid CRL distribution point")
+		}
+		if !dpNamePresent {
+			continue
+		}
+		if !dpNameDER.ReadASN1(&dpNameDER, cryptobyte_asn1.Tag(0).Constructed().ContextSpecific()) {
+			return nil, errors.New("x509: invalid CRL distribution point")
+		}
+		for !dpNameDER.Empty() {
+			if !dpNameDER.PeekASN1Tag(cryptobyte_asn1.Tag(6).ContextSpecific()) {
+				break
+			}
+			var uri cryptobyte.String
+			if !dpNameDER.ReadASN1(&uri, cryptobyte_asn1.Tag(6).ContextSpecific()) {
+				return nil, errors.New("x509: invalid CRL distribution point")
+			}
+			cdp = append(cdp, string(uri))
+		}
+	}
+	return cdp, nil
+}
+
 func fetchCRL(ctx context.Context, crlURL string, client *http.Client) (*x509.RevocationList, error) {
 	// validate URL
 	parsedURL, err := url.Parse(crlURL)
diff --git a/revocation/crl/fetcher_test.go b/revocation/crl/fetcher_test.go
index 634fbc3a..87fc0dd6 100644
--- a/revocation/crl/fetcher_test.go
+++ b/revocation/crl/fetcher_test.go
@@ -19,11 +19,13 @@ import (
 	"crypto/rand"
 	"crypto/x509"
 	"crypto/x509/pkix"
+	"encoding/pem"
 	"errors"
 	"fmt"
 	"io"
 	"math/big"
 	"net/http"
+	"os"
 	"strings"
 	"sync"
 	"testing"
@@ -195,39 +197,6 @@ func TestFetch(t *testing.T) {
 		}
 	})
 
-	t.Run("delta CRL is not supported", func(t *testing.T) {
-		c := &memoryCache{}
-		// prepare a CRL with refresh CRL extension
-		certChain := testhelper.GetRevokableRSAChainWithRevocations(2, false, true)
-		expiredCRLBytes, err := x509.CreateRevocationList(rand.Reader, &x509.RevocationList{
-			Number:     big.NewInt(1),
-			NextUpdate: time.Now().Add(-1 * time.Hour),
-			ExtraExtensions: []pkix.Extension{
-				{
-					Id:    oidFreshestCRL,
-					Value: []byte{0x01, 0x02, 0x03},
-				},
-			},
-		}, certChain[1].Cert, certChain[1].PrivateKey)
-		if err != nil {
-			t.Fatalf("failed to create base CRL: %v", err)
-		}
-
-		httpClient := &http.Client{
-			Transport: expectedRoundTripperMock{Body: expiredCRLBytes},
-		}
-		f, err := NewHTTPFetcher(httpClient)
-		if err != nil {
-			t.Errorf("NewHTTPFetcher() error = %v, want nil", err)
-		}
-		f.Cache = c
-		f.DiscardCacheError = true
-		_, err = f.Fetch(context.Background(), uncachedURL)
-		if !strings.Contains(err.Error(), "delta CRL is not supported") {
-			t.Errorf("Fetcher.Fetch() error = %v, want delta CRL is not supported", err)
-		}
-	})
-
 	t.Run("Set cache error", func(t *testing.T) {
 		c := &errorCache{
 			GetError: ErrCacheMiss,
@@ -291,6 +260,212 @@ func TestFetch(t *testing.T) {
 	})
 }
 
+func TestParseFreshestCRL(t *testing.T) {
+	loadExtentsion := func(certPath string) pkix.Extension {
+		certData, err := os.ReadFile(certPath)
+		if err != nil {
+			t.Fatalf("failed to read certificate: %v", err)
+		}
+
+		block, _ := pem.Decode(certData)
+		if block == nil {
+			t.Fatalf("failed to decode PEM block")
+		}
+
+		cert, err := x509.ParseCertificate(block.Bytes)
+		if err != nil {
+			t.Fatalf("failed to parse certificate: %v", err)
+		}
+
+		for _, ext := range cert.Extensions {
+			if ext.Id.Equal([]int{2, 5, 29, 46}) { // id-ce-freshestCRL
+				return ext
+			}
+		}
+
+		t.Fatalf("freshestCRL extension not found")
+		return pkix.Extension{}
+	}
+
+	t.Run("valid 1 delta CRL URL", func(t *testing.T) {
+		certPath := "testdata/certificateWithDeltaCRL.cer"
+		freshestCRLExtension := loadExtentsion(certPath)
+		urls, err := parseFreshestCRL(freshestCRLExtension)
+		if err != nil {
+			t.Fatalf("failed to parse freshest CRL: %v", err)
+		}
+
+		if len(urls) != 1 {
+			t.Fatalf("expected 1 URL, got %d", len(urls))
+		}
+
+		if !strings.HasPrefix(urls[0], "http://localhost:80") {
+			t.Fatalf("unexpected URL: %s", urls[0])
+		}
+	})
+
+	t.Run("empty extension", func(t *testing.T) {
+		_, err := parseFreshestCRL(pkix.Extension{})
+		if err == nil {
+			t.Fatalf("expected error")
+		}
+	})
+
+	t.Run("URL doesn't exist", func(t *testing.T) {
+		certPath := "testdata/certificateWithZeroDeltaCRLURL.cer"
+		freshestCRLExtension := loadExtentsion(certPath)
+		url, err := parseFreshestCRL(freshestCRLExtension)
+		if err != nil {
+			t.Fatalf("failed to parse freshest CRL: %v", err)
+		}
+		if len(url) != 0 {
+			t.Fatalf("expected 0 URL, got %d", len(url))
+		}
+	})
+
+	t.Run("non URI freshest CRL extension", func(t *testing.T) {
+		certPath := "testdata/certificateWithNonURIDeltaCRL.cer"
+		freshestCRLExtension := loadExtentsion(certPath)
+		url, err := parseFreshestCRL(freshestCRLExtension)
+		if err != nil {
+			t.Fatalf("failed to parse freshest CRL: %v", err)
+		}
+		if len(url) != 0 {
+			t.Fatalf("expected 0 URL, got %d", len(url))
+		}
+	})
+
+	t.Run("certificate with incomplete freshest CRL extension", func(t *testing.T) {
+		certPath := "testdata/certificateWithIncompleteFreshestCRL.cer"
+		freshestCRLExtension := loadExtentsion(certPath)
+		_, err := parseFreshestCRL(freshestCRLExtension)
+		expectErrorMsg := "x509: invalid CRL distribution point"
+		if err == nil || err.Error() != expectErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectErrorMsg, err)
+		}
+	})
+
+	t.Run("certificate with incomplete freshest CRL extension2", func(t *testing.T) {
+		certPath := "testdata/certificateWithIncompleteFreshestCRL2.cer"
+		freshestCRLExtension := loadExtentsion(certPath)
+		url, err := parseFreshestCRL(freshestCRLExtension)
+		if err != nil {
+			t.Fatalf("failed to parse freshest CRL: %v", err)
+		}
+		if len(url) != 0 {
+			t.Fatalf("expected 0 URL, got %d", len(url))
+		}
+	})
+}
+
+func TestProcessDeltaCRL(t *testing.T) {
+	loadExtentsion := func(certPath string) *[]pkix.Extension {
+		certData, err := os.ReadFile(certPath)
+		if err != nil {
+			t.Fatalf("failed to read certificate: %v", err)
+		}
+
+		block, _ := pem.Decode(certData)
+		if block == nil {
+			t.Fatalf("failed to decode PEM block")
+		}
+
+		cert, err := x509.ParseCertificate(block.Bytes)
+		if err != nil {
+			t.Fatalf("failed to parse certificate: %v", err)
+		}
+
+		return &cert.Extensions
+	}
+
+	deltaCRL, err := os.ReadFile("testdata/delta.crl")
+	if err != nil {
+		t.Fatalf("failed to read delta CRL: %v", err)
+	}
+
+	fetcher, err := NewHTTPFetcher(&http.Client{
+		Transport: expectedRoundTripperMock{Body: deltaCRL},
+	})
+	if err != nil {
+		t.Fatalf("failed to create fetcher: %v", err)
+	}
+
+	t.Run("parse freshest CRL failed", func(t *testing.T) {
+		certPath := "testdata/certificateWithIncompleteFreshestCRL.cer"
+		extensions := loadExtentsion(certPath)
+		_, err := fetcher.processDeltaCRL(extensions)
+		expectedErrorMsg := "failed to parse Freshest CRL extension: x509: invalid CRL distribution point"
+		if err == nil || err.Error() != expectedErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectedErrorMsg, err)
+		}
+	})
+
+	t.Run("zero freshest CRL URL", func(t *testing.T) {
+		certPath := "testdata/certificateWithZeroDeltaCRLURL.cer"
+		extensions := loadExtentsion(certPath)
+		deltaCRL, err := fetcher.processDeltaCRL(extensions)
+		if err != nil {
+			t.Fatalf("failed to process delta CRL: %v", err)
+		}
+		if deltaCRL != nil {
+			t.Fatalf("expected nil delta CRL, got %v", deltaCRL)
+		}
+	})
+
+	t.Run("one freshest CRL URL", func(t *testing.T) {
+		certPath := "testdata/certificateWithDeltaCRL.cer"
+		extensions := loadExtentsion(certPath)
+		deltaCRL, err := fetcher.processDeltaCRL(extensions)
+		if err != nil {
+			t.Fatalf("failed to process delta CRL: %v", err)
+		}
+		if deltaCRL == nil {
+			t.Fatalf("expected non-nil delta CRL")
+		}
+	})
+
+	t.Run("multiple freshest CRL URLs", func(t *testing.T) {
+		certPath := "testdata/certificateWith2DeltaCRL.cer"
+		extensions := loadExtentsion(certPath)
+		_, err := fetcher.processDeltaCRL(extensions)
+		expectedErrorMsg := "multiple Freshest CRL distribution points are not supported"
+		if err == nil || err.Error() != expectedErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectedErrorMsg, err)
+		}
+	})
+
+	t.Run("process delta crl from certificate extension failed", func(t *testing.T) {
+		certPath := "testdata/certificateWithIncompleteFreshestCRL.cer"
+		extensions := loadExtentsion(certPath)
+		_, err := fetcher.fetch(context.Background(), "http://localhost.test", extensions)
+		expectedErrorMsg := "failed to parse Freshest CRL extension: x509: invalid CRL distribution point"
+		if err == nil || err.Error() != expectedErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectedErrorMsg, err)
+		}
+	})
+
+	crlFile, err := os.ReadFile("testdata/crlWithMultipleFreshestCRLs.crl")
+	if err != nil {
+		t.Fatalf("failed to read CRL file: %v", err)
+	}
+	fetcher, err = NewHTTPFetcher(&http.Client{
+		Transport: expectedRoundTripperMock{Body: crlFile},
+	})
+	if err != nil {
+		t.Fatalf("failed to create fetcher: %v", err)
+	}
+
+	t.Run("fetch delta CRL from CRL failed", func(t *testing.T) {
+		certPath := "testdata/certificateWithDeltaCRL.cer"
+		extensions := loadExtentsion(certPath)
+		_, err := fetcher.fetch(context.Background(), "http://localhost.test", extensions)
+		expectErrorMsg := "multiple Freshest CRL distribution points are not supported"
+		if err == nil || err.Error() != expectErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectErrorMsg, err)
+		}
+	})
+}
+
 func TestDownload(t *testing.T) {
 	t.Run("parse url error", func(t *testing.T) {
 		_, err := fetchCRL(context.Background(), ":", http.DefaultClient)
diff --git a/revocation/crl/testdata/certificateWith2DeltaCRL.cer b/revocation/crl/testdata/certificateWith2DeltaCRL.cer
new file mode 100644
index 00000000..3d029b2a
--- /dev/null
+++ b/revocation/crl/testdata/certificateWith2DeltaCRL.cer
@@ -0,0 +1,32 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/revocation/crl/testdata/certificateWithDeltaCRL.cer b/revocation/crl/testdata/certificateWithDeltaCRL.cer
new file mode 100644
index 00000000..8b06be8d
--- /dev/null
+++ b/revocation/crl/testdata/certificateWithDeltaCRL.cer
@@ -0,0 +1,28 @@
+-----BEGIN CERTIFICATE-----
+MIIE1TCCAz2gAwIBAgIUaHnHWrIVx0qzAZIwvELkQUEs+3cwDQYJKoZIhvcNAQEL
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+ewhVgLUqtg/YqnmNYJp0u8jC7YHSPt4D4vA3YwFZ2WF1FNI5WQgKNZQ=
+-----END CERTIFICATE-----
diff --git a/revocation/crl/testdata/certificateWithIncompleteFreshestCRL.cer b/revocation/crl/testdata/certificateWithIncompleteFreshestCRL.cer
new file mode 100644
index 00000000..35776859
--- /dev/null
+++ b/revocation/crl/testdata/certificateWithIncompleteFreshestCRL.cer
@@ -0,0 +1,22 @@
+-----BEGIN CERTIFICATE-----
+MIIDmTCCAgGgAwIBAgIUaHnHWrIVx0qzAZIwvELkQUEs+3cwDQYJKoZIhvcNAQEL
+BQAwYTEjMCEGCgmSJomT8ixkAQEME2MtMG53d296cXZhd3ZhbzNlY2gxFTATBgNV
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+3G3HbuwIdw+c6r4nhoKGLfKsntZ7CFWAtSq2D9iqeY1gmnS7yMLtgdI+3gPi8Ddj
+AVnZYXUU0jlZCAo1lA==
+-----END CERTIFICATE-----
diff --git a/revocation/crl/testdata/certificateWithIncompleteFreshestCRL2.cer b/revocation/crl/testdata/certificateWithIncompleteFreshestCRL2.cer
new file mode 100644
index 00000000..8ef955fc
--- /dev/null
+++ b/revocation/crl/testdata/certificateWithIncompleteFreshestCRL2.cer
@@ -0,0 +1,22 @@
+-----BEGIN CERTIFICATE-----
+MIIDlzCCAf+gAwIBAgIUaHnHWrIVx0qzAZIwvELkQUEs+3cwDQYJKoZIhvcNAQEL
+BQAwYTEjMCEGCgmSJomT8ixkAQEME2MtMG53d296cXZhd3ZhbzNlY2gxFTATBgNV
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+x27sCHcPnOq+J4aChi3yrJ7WewhVgLUqtg/YqnmNYJp0u8jC7YHSPt4D4vA3YwFZ
+2WF1FNI5WQgKNZQ=
+-----END CERTIFICATE-----
diff --git a/revocation/crl/testdata/certificateWithNonURIDeltaCRL.cer b/revocation/crl/testdata/certificateWithNonURIDeltaCRL.cer
new file mode 100644
index 00000000..128bbbe9
--- /dev/null
+++ b/revocation/crl/testdata/certificateWithNonURIDeltaCRL.cer
@@ -0,0 +1,22 @@
+-----BEGIN CERTIFICATE-----
+MIIDnjCCAgagAwIBAgIUaHnHWrIVx0qzAZIwvELkQUEs+3cwDQYJKoZIhvcNAQEL
+BQAwYTEjMCEGCgmSJomT8ixkAQEME2MtMG53d296cXZhd3ZhbzNlY2gxFTATBgNV
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+KJAUBubcbcdu7Ah3D5zqvieGgoYt8qye1nsIVYC1KrYP2Kp5jWCadLvIwu2B0j7e
+A+LwN2MBWdlhdRTSOVkICjWU
+-----END CERTIFICATE-----
diff --git a/revocation/crl/testdata/certificateWithZeroDeltaCRLURL.cer b/revocation/crl/testdata/certificateWithZeroDeltaCRLURL.cer
new file mode 100644
index 00000000..6f4de65e
--- /dev/null
+++ b/revocation/crl/testdata/certificateWithZeroDeltaCRLURL.cer
@@ -0,0 +1,25 @@
+-----BEGIN CERTIFICATE-----
+MIIENTCCAp2gAwIBAgIUaHnHWrIVx0qzAZIwvELkQUEs+3cwDQYJKoZIhvcNAQEL
+BQAwYTEjMCEGCgmSJomT8ixkAQEME2MtMG53d296cXZhd3ZhbzNlY2gxFTATBgNV
+BAMMDE1hbmFnZW1lbnRDQTEjMCEGA1UECgwaRUpCQ0EgQ29udGFpbmVyIFF1aWNr
+c3RhcnQwHhcNMjQxMTI1MDc1NzI3WhcNMjYxMTI1MDc1NzI2WjAYMRYwFAYDVQQD
+DA1Ob3RhdGlvblRlc3QzMIGbMBAGByqGSM49AgEGBSuBBAAjA4GGAAQAuJlXlrTm
+VhEiLz75HgJlZGm0TE7W/7mYn0m03vV+9tBEA/ZV50ACkMDY0ewxxh4Ko6UsGq71
+E466hSVggiaYaE4AdbL5kAolsnEm9/EDfYQNfgiQw0BI7axri9tJ19yZhj4Es31+
+j4RJHAydB4i/qJi6T8cITdT6ViyzWM6AWGl7yRajggE0MIIBMDAMBgNVHRMBAf8E
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+cagW0M6dpaDcnA0Zl/eX2uxFecXDyFL+Ngfk8y7v2p5/RSzjJKhIQPhec7BKJopF
+APi+HLiFi11IcCFsBNiP6X4ByetSbTDMb961kB8qOmKc6SABtt6MRl865TeP6DX1
+s1jCGJXJeMYh8QtrzipzTsCHdwpN47CRNdLSJnQ/7UGF4e4ebnhEsj1GbajP4NkD
+2qfrRBwK6YHwEHaRL0Y9b2VgKLXBCK/muaaKROelGhOGtvQ7KVUwNa1XIYSmJdoK
+Q8YnkkIEK+tX1h180aCnHRWfjYKibsHfQsa125JehCg6Xn4r8M/RuG92+kfJTJfs
+Jnk4D70lGDt+HPBrBdeNx1f1SjaAb6M+OEMi1H/tfl4h7lI3x2lwrV5gzqEOuDN3
+fYBq89txuSiQFAbm3G3HbuwIdw+c6r4nhoKGLfKsntZ7CFWAtSq2D9iqeY1gmnS7
+yMLtgdI+3gPi8DdjAVnZYXUU0jlZCAo1lA==
+-----END CERTIFICATE-----
diff --git a/revocation/crl/testdata/crlWithMultipleFreshestCRLs.crl b/revocation/crl/testdata/crlWithMultipleFreshestCRLs.crl
new file mode 100644
index 00000000..49e5f5e0
Binary files /dev/null and b/revocation/crl/testdata/crlWithMultipleFreshestCRLs.crl differ
diff --git a/revocation/crl/testdata/delta.crl b/revocation/crl/testdata/delta.crl
new file mode 100644
index 00000000..8281417a
Binary files /dev/null and b/revocation/crl/testdata/delta.crl differ
diff --git a/revocation/internal/crl/const.go b/revocation/internal/crl/const.go
new file mode 100644
index 00000000..a58ce967
--- /dev/null
+++ b/revocation/internal/crl/const.go
@@ -0,0 +1,32 @@
+// Copyright The Notary Project Authors.
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package crl
+
+const (
+	// RFC 5280, 5.3.1
+	// CRLReason ::= ENUMERATED {
+	//   unspecified             (0),
+	//   keyCompromise           (1),
+	//   cACompromise            (2),
+	//   affiliationChanged      (3),
+	//   superseded              (4),
+	//   cessationOfOperation    (5),
+	//   certificateHold         (6),
+	//        -- value 7 is not used
+	//   removeFromCRL           (8),
+	//   privilegeWithdrawn      (9),
+	//   aACompromise           (10) }
+	reasonCodeCertificateHold = 6
+	reasonCodeRemoveFromCRL   = 8
+)
diff --git a/revocation/internal/crl/crl.go b/revocation/internal/crl/crl.go
index 50f2c085..c5684ad8 100644
--- a/revocation/internal/crl/crl.go
+++ b/revocation/internal/crl/crl.go
@@ -21,10 +21,12 @@ import (
 	"encoding/asn1"
 	"errors"
 	"fmt"
+	"math/big"
 	"time"
 
 	"github.com/notaryproject/notation-core-go/revocation/crl"
 	"github.com/notaryproject/notation-core-go/revocation/result"
+	"golang.org/x/crypto/cryptobyte"
 )
 
 var (
@@ -36,6 +38,10 @@ var (
 	// distribution point CRL extension. (See RFC 5280, Section 5.2.5)
 	oidIssuingDistributionPoint = asn1.ObjectIdentifier{2, 5, 29, 28}
 
+	// oidDeltaCRLIndicator is the object identifier for the delta CRL indicator
+	// (See RFC 5280, Section 5.2.4)
+	oidDeltaCRLIndicator = asn1.ObjectIdentifier{2, 5, 29, 27}
+
 	// oidInvalidityDate is the object identifier for the invalidity date
 	// CRL entry extension. (See RFC 5280, Section 5.3.2)
 	oidInvalidityDate = asn1.ObjectIdentifier{2, 5, 29, 24}
@@ -89,6 +95,7 @@ func CertCheckStatus(ctx context.Context, cert, issuer *x509.Certificate, opts C
 		serverResults = make([]*result.ServerResult, 0, len(cert.CRLDistributionPoints))
 		lastErr       error
 		crlURL        string
+		hasDeltaCRL   = hasDeltaCRL(cert)
 	)
 
 	// The CRLDistributionPoints contains the URIs of all the CRL distribution
@@ -99,18 +106,35 @@ func CertCheckStatus(ctx context.Context, cert, issuer *x509.Certificate, opts C
 	// point with one CRL URI, which will be cached, so checking all the URIs is
 	// not a performance issue.
 	for _, crlURL = range cert.CRLDistributionPoints {
-		bundle, err := opts.Fetcher.Fetch(ctx, crlURL)
-		if err != nil {
-			lastErr = fmt.Errorf("failed to download CRL from %s: %w", crlURL, err)
-			break
+		var (
+			bundle *crl.Bundle
+			err    error
+		)
+		if !hasDeltaCRL {
+			bundle, err = opts.Fetcher.Fetch(ctx, crlURL)
+			if err != nil {
+				lastErr = fmt.Errorf("failed to download CRL from %s: %w", crlURL, err)
+				break
+			}
+		} else {
+			fetcher, ok := opts.Fetcher.(crl.FetcherWithCertificateExtensions)
+			if !ok {
+				lastErr = fmt.Errorf("fetcher does not support fetching delta CRL from certificate extension")
+				break
+			}
+			bundle, err = fetcher.FetchWithCertificateExtensions(ctx, crlURL, &cert.Extensions)
+			if err != nil {
+				lastErr = fmt.Errorf("failed to download CRL from %s: %w", crlURL, err)
+				break
+			}
 		}
 
-		if err = validate(bundle.BaseCRL, issuer); err != nil {
+		if err = validate(bundle, issuer); err != nil {
 			lastErr = fmt.Errorf("failed to validate CRL from %s: %w", crlURL, err)
 			break
 		}
 
-		crlResult, err := checkRevocation(cert, bundle.BaseCRL, opts.SigningTime, crlURL)
+		crlResult, err := checkRevocation(cert, bundle, opts.SigningTime, crlURL)
 		if err != nil {
 			lastErr = fmt.Errorf("failed to check revocation status from %s: %w", crlURL, err)
 			break
@@ -153,7 +177,56 @@ func Supported(cert *x509.Certificate) bool {
 	return cert != nil && len(cert.CRLDistributionPoints) > 0
 }
 
-func validate(crl *x509.RevocationList, issuer *x509.Certificate) error {
+func hasDeltaCRL(cert *x509.Certificate) bool {
+	for _, ext := range cert.Extensions {
+		if ext.Id.Equal(oidFreshestCRL) {
+			return true
+		}
+	}
+	return false
+}
+
+func validate(bundle *crl.Bundle, issuer *x509.Certificate) error {
+	// validate base CRL
+	baseCRL := bundle.BaseCRL
+	if err := validateCRL(baseCRL, issuer); err != nil {
+		return fmt.Errorf("failed to validate base CRL: %w", err)
+	}
+
+	if bundle.DeltaCRL != nil {
+		// validate delta CRL
+		// RFC 5280, Section 5.2.4
+		deltaCRL := bundle.DeltaCRL
+		if err := validateCRL(deltaCRL, issuer); err != nil {
+			return fmt.Errorf("failed to validate delta CRL: %w", err)
+		}
+
+		if deltaCRL.Number.Cmp(baseCRL.Number) <= 0 {
+			return fmt.Errorf("delta CRL number %d is not greater than the base CRL number %d", deltaCRL.Number, baseCRL.Number)
+		}
+		// check delta CRL indicator extension
+		var minimumBaseCRLNumber *big.Int
+		for _, ext := range deltaCRL.Extensions {
+			if ext.Id.Equal(oidDeltaCRLIndicator) {
+				minimumBaseCRLNumber = new(big.Int)
+				value := cryptobyte.String(ext.Value)
+				if !value.ReadASN1Integer(minimumBaseCRLNumber) {
+					return errors.New("failed to parse delta CRL indicator extension")
+				}
+				break
+			}
+		}
+		if minimumBaseCRLNumber == nil {
+			return errors.New("delta CRL indicator extension is not found")
+		}
+		if minimumBaseCRLNumber.Cmp(baseCRL.Number) > 0 {
+			return fmt.Errorf("delta CRL indicator %d is not less than or equal to the base CRL number %d", minimumBaseCRLNumber, baseCRL.Number)
+		}
+	}
+	return nil
+}
+
+func validateCRL(crl *x509.RevocationList, issuer *x509.Certificate) error {
 	// check signature
 	if err := crl.CheckSignatureFrom(issuer); err != nil {
 		return fmt.Errorf("CRL is not signed by CA %s: %w,", issuer.Subject, err)
@@ -170,12 +243,12 @@ func validate(crl *x509.RevocationList, issuer *x509.Certificate) error {
 
 	for _, ext := range crl.Extensions {
 		switch {
-		case ext.Id.Equal(oidFreshestCRL):
-			return errors.New("delta CRL is not supported")
 		case ext.Id.Equal(oidIssuingDistributionPoint):
 			// IssuingDistributionPoint is a critical extension that identifies
 			// the scope of the CRL. Since we will check all the CRL
 			// distribution points, it is not necessary to check this extension.
+		case ext.Id.Equal(oidDeltaCRLIndicator):
+			// will be checked in validate()
 		default:
 			if ext.Critical {
 				// unsupported critical extensions is not allowed. (See RFC 5280, Section 5.2)
@@ -188,38 +261,73 @@ func validate(crl *x509.RevocationList, issuer *x509.Certificate) error {
 }
 
 // checkRevocation checks if the certificate is revoked or not
-func checkRevocation(cert *x509.Certificate, baseCRL *x509.RevocationList, signingTime time.Time, crlURL string) (*result.ServerResult, error) {
+func checkRevocation(cert *x509.Certificate, b *crl.Bundle, signingTime time.Time, crlURL string) (*result.ServerResult, error) {
 	if cert == nil {
 		return nil, errors.New("certificate cannot be nil")
 	}
-
-	if baseCRL == nil {
+	if b == nil {
+		return nil, errors.New("CRL bundle cannot be nil")
+	}
+	if b.BaseCRL == nil {
 		return nil, errors.New("baseCRL cannot be nil")
 	}
 
-	for _, revocationEntry := range baseCRL.RevokedCertificateEntries {
-		if revocationEntry.SerialNumber.Cmp(cert.SerialNumber) == 0 {
-			extensions, err := parseEntryExtensions(revocationEntry)
-			if err != nil {
-				return nil, err
-			}
+	entriesBundle := []*[]x509.RevocationListEntry{&b.BaseCRL.RevokedCertificateEntries}
+	if b.DeltaCRL != nil {
+		entriesBundle = append(entriesBundle, &b.DeltaCRL.RevokedCertificateEntries)
+	}
 
-			// validate signingTime and invalidityDate
-			if !signingTime.IsZero() && !extensions.invalidityDate.IsZero() &&
-				signingTime.Before(extensions.invalidityDate) {
-				// signing time is before the invalidity date which means the
-				// certificate is not revoked at the time of signing.
-				break
+	// latestTempRevokedEntry contains the most recent revocation entry with
+	// reasons such as CertificateHold or RemoveFromCRL.
+	//
+	// If the certificate is revoked with CertificateHold, it is temporarily
+	// revoked. If the certificate is shown in the CRL with RemoveFromCRL,
+	// it is unrevoked.
+	var latestTempRevokedEntry *x509.RevocationListEntry
+
+	// iterate over all the entries in the base and delta CRLs
+	for _, entries := range entriesBundle {
+		for i, revocationEntry := range *entries {
+			if revocationEntry.SerialNumber.Cmp(cert.SerialNumber) == 0 {
+				extensions, err := parseEntryExtensions(revocationEntry)
+				if err != nil {
+					return nil, err
+				}
+
+				// validate signingTime and invalidityDate
+				if !signingTime.IsZero() && !extensions.invalidityDate.IsZero() &&
+					signingTime.Before(extensions.invalidityDate) {
+					// signing time is before the invalidity date which means the
+					// certificate is not revoked at the time of signing.
+					break
+				}
+
+				switch revocationEntry.ReasonCode {
+				case int(reasonCodeCertificateHold), int(reasonCodeRemoveFromCRL):
+					// temporarily revoked or unrevoked
+					if latestTempRevokedEntry == nil || latestTempRevokedEntry.RevocationTime.Before(revocationEntry.RevocationTime) {
+						// the revocation status depends on the most recent reason
+						latestTempRevokedEntry = &(*entries)[i]
+					}
+				default:
+					// permanently revoked
+					return &result.ServerResult{
+						Result:           result.ResultRevoked,
+						Server:           crlURL,
+						RevocationMethod: result.RevocationMethodCRL,
+					}, nil
+				}
 			}
-
-			// revoked
-			return &result.ServerResult{
-				Result:           result.ResultRevoked,
-				Server:           crlURL,
-				RevocationMethod: result.RevocationMethodCRL,
-			}, nil
 		}
 	}
+	if latestTempRevokedEntry != nil && latestTempRevokedEntry.ReasonCode == reasonCodeCertificateHold {
+		// revoked with CertificateHold
+		return &result.ServerResult{
+			Result:           result.ResultRevoked,
+			Server:           crlURL,
+			RevocationMethod: result.RevocationMethodCRL,
+		}, nil
+	}
 
 	return &result.ServerResult{
 		Result:           result.ResultOK,
diff --git a/revocation/internal/crl/crl_test.go b/revocation/internal/crl/crl_test.go
index 27fa2475..53af4fc4 100644
--- a/revocation/internal/crl/crl_test.go
+++ b/revocation/internal/crl/crl_test.go
@@ -203,38 +203,6 @@ func TestCertCheckStatus(t *testing.T) {
 		}
 	})
 
-	t.Run("CRL with delta CRL is not checked", func(t *testing.T) {
-		memoryCache := &memoryCache{}
-
-		crlBytes, err := x509.CreateRevocationList(rand.Reader, &x509.RevocationList{
-			NextUpdate: time.Now().Add(time.Hour),
-			Number:     big.NewInt(20240720),
-			ExtraExtensions: []pkix.Extension{
-				{
-					Id:       oidFreshestCRL,
-					Critical: false,
-				},
-			},
-		}, issuerCert, issuerKey)
-		if err != nil {
-			t.Fatal(err)
-		}
-		fetcher, err := crlutils.NewHTTPFetcher(
-			&http.Client{Transport: expectedRoundTripperMock{Body: crlBytes}},
-		)
-		if err != nil {
-			t.Fatal(err)
-		}
-		fetcher.Cache = memoryCache
-		fetcher.DiscardCacheError = true
-		r := CertCheckStatus(context.Background(), chain[0].Cert, issuerCert, CertCheckStatusOptions{
-			Fetcher: fetcher,
-		})
-		if !strings.Contains(r.ServerResults[0].Error.Error(), "delta CRL is not supported") {
-			t.Fatalf("unexpected error, got %v, expected %v", r.ServerResults[0].Error, "delta CRL is not supported")
-		}
-	})
-
 	memoryCache := &memoryCache{}
 
 	// create a stale CRL
@@ -328,6 +296,74 @@ func TestCertCheckStatus(t *testing.T) {
 			t.Fatalf("expected OK, got %s", r.Result)
 		}
 	})
+
+	t.Run("certificate with invalid freshest crl extension", func(t *testing.T) {
+		chain[0].Cert.Extensions = []pkix.Extension{
+			{
+				Id:    oidFreshestCRL,
+				Value: []byte("invalid"),
+			},
+		}
+
+		crlBytes, err := x509.CreateRevocationList(rand.Reader, &x509.RevocationList{
+			NextUpdate: time.Now().Add(time.Hour),
+			Number:     big.NewInt(20240720),
+		}, issuerCert, issuerKey)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		fetcher, err := crlutils.NewHTTPFetcher(
+			&http.Client{Transport: expectedRoundTripperMock{Body: crlBytes}},
+		)
+		if err != nil {
+			t.Fatal(err)
+		}
+		fetcher.DiscardCacheError = true
+		r := CertCheckStatus(context.Background(), chain[0].Cert, issuerCert, CertCheckStatusOptions{
+			Fetcher: fetcher,
+		})
+		if r.Result != result.ResultUnknown {
+			t.Fatalf("expected Unknown, got %s", r.Result)
+		}
+		expectedErrorMsg := "failed to download CRL from http://localhost.test: failed to retrieve CRL: failed to parse Freshest CRL extension: x509: invalid CRL distribution points"
+		if r.ServerResults[0].Error == nil || r.ServerResults[0].Error.Error() != expectedErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectedErrorMsg, r.ServerResults[0].Error)
+		}
+	})
+
+	t.Run("fetcher doesn't support delta CRL", func(t *testing.T) {
+		chain[0].Cert.CRLDistributionPoints = []string{"http://localhost.test"}
+		chain[0].Cert.Extensions = []pkix.Extension{
+			{
+				Id:    oidFreshestCRL,
+				Value: []byte{0x00},
+			},
+		}
+
+		fetcher := &fetcherMock{}
+		if err != nil {
+			t.Fatal(err)
+		}
+		r := CertCheckStatus(context.Background(), chain[0].Cert, issuerCert, CertCheckStatusOptions{
+			Fetcher: fetcher,
+		})
+		if r.Result != result.ResultUnknown {
+			t.Fatalf("expected Unknown, got %s", r.Result)
+		}
+
+		expectedErrorMsg := "fetcher does not support fetching delta CRL from certificate extension"
+		if r.ServerResults[0].Error == nil || r.ServerResults[0].Error.Error() != expectedErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectedErrorMsg, r.ServerResults[0].Error)
+		}
+	})
+
+}
+
+type fetcherMock struct{}
+
+func (f *fetcherMock) Fetch(ctx context.Context, url string) (*crlutils.Bundle, error) {
+	return nil, fmt.Errorf("fetch error")
 }
 
 func TestValidate(t *testing.T) {
@@ -349,7 +385,7 @@ func TestValidate(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		if err := validate(crl, issuerCert); err == nil {
+		if err := validateCRL(crl, issuerCert); err == nil {
 			t.Fatal("expected error")
 		}
 	})
@@ -359,7 +395,7 @@ func TestValidate(t *testing.T) {
 			NextUpdate: time.Now().Add(time.Hour),
 		}
 
-		if err := validate(crl, &x509.Certificate{}); err == nil {
+		if err := validateCRL(crl, &x509.Certificate{}); err == nil {
 			t.Fatal("expected error")
 		}
 	})
@@ -390,7 +426,7 @@ func TestValidate(t *testing.T) {
 			},
 		}
 
-		if err := validate(crl, issuerCert); err == nil {
+		if err := validateCRL(crl, issuerCert); err == nil {
 			t.Fatal("expected error")
 		}
 	})
@@ -419,37 +455,215 @@ func TestValidate(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		if err := validate(crl, issuerCert); err != nil {
+		if err := validateCRL(crl, issuerCert); err != nil {
 			t.Fatal(err)
 		}
 	})
 
-	t.Run("delta CRL is not supported", func(t *testing.T) {
-		chain := testhelper.GetRevokableRSAChainWithRevocations(1, false, true)
-		issuerCert := chain[0].Cert
-		issuerKey := chain[0].PrivateKey
+	chain := testhelper.GetRevokableRSAChainWithRevocations(1, false, true)
+	issuerCert := chain[0].Cert
+	issuerKey := chain[0].PrivateKey
 
-		crlBytes, err := x509.CreateRevocationList(rand.Reader, &x509.RevocationList{
+	crlBytes, err := x509.CreateRevocationList(rand.Reader, &x509.RevocationList{
+		NextUpdate: time.Now().Add(time.Hour),
+		Number:     big.NewInt(20240720),
+	}, issuerCert, issuerKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	crl, err := x509.ParseRevocationList(crlBytes)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	t.Run("valid crl and delta crl", func(t *testing.T) {
+		deltaCRLIndicator := big.NewInt(20240720)
+		deltaCRLIndicatorBytes, err := asn1.Marshal(deltaCRLIndicator)
+		if err != nil {
+			t.Fatal(err)
+		}
+		deltaCRLBytes, err := x509.CreateRevocationList(rand.Reader, &x509.RevocationList{
 			NextUpdate: time.Now().Add(time.Hour),
-			Number:     big.NewInt(20240720),
+			Number:     big.NewInt(20240721),
 			ExtraExtensions: []pkix.Extension{
 				{
-					Id:       oidFreshestCRL,
-					Critical: false,
+					Id:       oidDeltaCRLIndicator,
+					Critical: true,
+					Value:    deltaCRLIndicatorBytes,
 				},
 			},
 		}, issuerCert, issuerKey)
 		if err != nil {
 			t.Fatal(err)
 		}
+		deltaCRL, err := x509.ParseRevocationList(deltaCRLBytes)
+		if err != nil {
+			t.Fatal(err)
+		}
+		bundle := &crlutils.Bundle{
+			BaseCRL:  crl,
+			DeltaCRL: deltaCRL,
+		}
+		if err := validate(bundle, issuerCert); err != nil {
+			t.Fatal(err)
+		}
+	})
 
-		crl, err := x509.ParseRevocationList(crlBytes)
+	t.Run("invalid delta crl", func(t *testing.T) {
+		deltaCRLIndicator := big.NewInt(20240720)
+		deltaCRLIndicatorBytes, err := asn1.Marshal(deltaCRLIndicator)
+		if err != nil {
+			t.Fatal(err)
+		}
+		deltaCRLBytes, err := x509.CreateRevocationList(rand.Reader, &x509.RevocationList{
+			Number: big.NewInt(20240721),
+			ExtraExtensions: []pkix.Extension{
+				{
+					Id:       oidDeltaCRLIndicator,
+					Critical: true,
+					Value:    deltaCRLIndicatorBytes,
+				},
+			},
+		}, issuerCert, issuerKey)
 		if err != nil {
 			t.Fatal(err)
 		}
+		deltaCRL, err := x509.ParseRevocationList(deltaCRLBytes)
+		if err != nil {
+			t.Fatal(err)
+		}
+		bundle := &crlutils.Bundle{
+			BaseCRL:  crl,
+			DeltaCRL: deltaCRL,
+		}
+		err = validate(bundle, issuerCert)
+		expectedErrorMsg := "failed to validate delta CRL: CRL NextUpdate is not set"
+		if err == nil || err.Error() != expectedErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectedErrorMsg, err)
+		}
+	})
 
-		if err := validate(crl, issuerCert); err.Error() != "delta CRL is not supported" {
-			t.Fatalf("got %v, expected delta CRL is not supported", err)
+	t.Run("invalid delta crl number", func(t *testing.T) {
+		deltaCRLIndicator := big.NewInt(20240720)
+		deltaCRLIndicatorBytes, err := asn1.Marshal(deltaCRLIndicator)
+		if err != nil {
+			t.Fatal(err)
+		}
+		deltaCRLBytes, err := x509.CreateRevocationList(rand.Reader, &x509.RevocationList{
+			NextUpdate: time.Now().Add(time.Hour),
+			Number:     big.NewInt(20240719),
+			ExtraExtensions: []pkix.Extension{
+				{
+					Id:       oidDeltaCRLIndicator,
+					Critical: true,
+					Value:    deltaCRLIndicatorBytes,
+				},
+			},
+		}, issuerCert, issuerKey)
+		if err != nil {
+			t.Fatal(err)
+		}
+		deltaCRL, err := x509.ParseRevocationList(deltaCRLBytes)
+		if err != nil {
+			t.Fatal(err)
+		}
+		bundle := &crlutils.Bundle{
+			BaseCRL:  crl,
+			DeltaCRL: deltaCRL,
+		}
+		err = validate(bundle, issuerCert)
+		expectedErrorMsg := "delta CRL number 20240719 is not greater than the base CRL number 20240720"
+		if err == nil || err.Error() != expectedErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectedErrorMsg, err)
+		}
+	})
+
+	t.Run("delta crl without delta crl indicator", func(t *testing.T) {
+		deltaCRLBytes, err := x509.CreateRevocationList(rand.Reader, &x509.RevocationList{
+			NextUpdate: time.Now().Add(time.Hour),
+			Number:     big.NewInt(20240721),
+		}, issuerCert, issuerKey)
+		if err != nil {
+			t.Fatal(err)
+		}
+		deltaCRL, err := x509.ParseRevocationList(deltaCRLBytes)
+		if err != nil {
+			t.Fatal(err)
+		}
+		bundle := &crlutils.Bundle{
+			BaseCRL:  crl,
+			DeltaCRL: deltaCRL,
+		}
+		err = validate(bundle, issuerCert)
+		expectedErrorMsg := "delta CRL indicator extension is not found"
+		if err == nil || err.Error() != expectedErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectedErrorMsg, err)
+		}
+	})
+
+	t.Run("delta crl minimum base crl number is greater than base crl", func(t *testing.T) {
+		deltaCRLIndicator := big.NewInt(20240721)
+		deltaCRLIndicatorBytes, err := asn1.Marshal(deltaCRLIndicator)
+		if err != nil {
+			t.Fatal(err)
+		}
+		deltaCRLBytes, err := x509.CreateRevocationList(rand.Reader, &x509.RevocationList{
+			NextUpdate: time.Now().Add(time.Hour),
+			Number:     big.NewInt(20240722),
+			ExtraExtensions: []pkix.Extension{
+				{
+					Id:       oidDeltaCRLIndicator,
+					Critical: true,
+					Value:    deltaCRLIndicatorBytes,
+				},
+			},
+		}, issuerCert, issuerKey)
+		if err != nil {
+			t.Fatal(err)
+		}
+		deltaCRL, err := x509.ParseRevocationList(deltaCRLBytes)
+		if err != nil {
+			t.Fatal(err)
+		}
+		bundle := &crlutils.Bundle{
+			BaseCRL:  crl,
+			DeltaCRL: deltaCRL,
+		}
+		err = validate(bundle, issuerCert)
+		expectedErrorMsg := "delta CRL indicator 20240721 is not less than or equal to the base CRL number 20240720"
+		if err == nil || err.Error() != expectedErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectedErrorMsg, err)
+		}
+	})
+
+	t.Run("delta crl with invalid delta indicator extension", func(t *testing.T) {
+		deltaCRLBytes, err := x509.CreateRevocationList(rand.Reader, &x509.RevocationList{
+			NextUpdate: time.Now().Add(time.Hour),
+			Number:     big.NewInt(20240722),
+			ExtraExtensions: []pkix.Extension{
+				{
+					Id:       oidDeltaCRLIndicator,
+					Critical: true,
+					Value:    []byte("invalid"),
+				},
+			},
+		}, issuerCert, issuerKey)
+		if err != nil {
+			t.Fatal(err)
+		}
+		deltaCRL, err := x509.ParseRevocationList(deltaCRLBytes)
+		if err != nil {
+			t.Fatal(err)
+		}
+		bundle := &crlutils.Bundle{
+			BaseCRL:  crl,
+			DeltaCRL: deltaCRL,
+		}
+		err = validate(bundle, issuerCert)
+		expectedErrorMsg := "failed to parse delta CRL indicator extension"
+		if err == nil || err.Error() != expectedErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectedErrorMsg, err)
 		}
 	})
 }
@@ -461,14 +675,22 @@ func TestCheckRevocation(t *testing.T) {
 	signingTime := time.Now()
 
 	t.Run("certificate is nil", func(t *testing.T) {
-		_, err := checkRevocation(nil, &x509.RevocationList{}, signingTime, "")
+		_, err := checkRevocation(nil, &crlutils.Bundle{BaseCRL: &x509.RevocationList{}}, signingTime, "")
 		if err == nil {
 			t.Fatal("expected error")
 		}
 	})
 
-	t.Run("CRL is nil", func(t *testing.T) {
+	t.Run("bundle is nil", func(t *testing.T) {
 		_, err := checkRevocation(cert, nil, signingTime, "")
+		expectedErrorMsg := "CRL bundle cannot be nil"
+		if err == nil || err.Error() != expectedErrorMsg {
+			t.Fatalf("expected error %q, got %v", expectedErrorMsg, err)
+		}
+	})
+
+	t.Run("CRL is nil", func(t *testing.T) {
+		_, err := checkRevocation(cert, &crlutils.Bundle{}, signingTime, "")
 		if err == nil {
 			t.Fatal("expected error")
 		}
@@ -482,7 +704,7 @@ func TestCheckRevocation(t *testing.T) {
 				},
 			},
 		}
-		r, err := checkRevocation(cert, baseCRL, signingTime, "")
+		r, err := checkRevocation(cert, &crlutils.Bundle{BaseCRL: baseCRL}, signingTime, "")
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -500,7 +722,7 @@ func TestCheckRevocation(t *testing.T) {
 				},
 			},
 		}
-		r, err := checkRevocation(cert, baseCRL, signingTime, "")
+		r, err := checkRevocation(cert, &crlutils.Bundle{BaseCRL: baseCRL}, signingTime, "")
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -533,7 +755,7 @@ func TestCheckRevocation(t *testing.T) {
 				},
 			},
 		}
-		r, err := checkRevocation(cert, baseCRL, signingTime, "")
+		r, err := checkRevocation(cert, &crlutils.Bundle{BaseCRL: baseCRL}, signingTime, "")
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -566,7 +788,7 @@ func TestCheckRevocation(t *testing.T) {
 				},
 			},
 		}
-		r, err := checkRevocation(cert, baseCRL, signingTime, "")
+		r, err := checkRevocation(cert, &crlutils.Bundle{BaseCRL: baseCRL}, signingTime, "")
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -584,7 +806,7 @@ func TestCheckRevocation(t *testing.T) {
 				},
 			},
 		}
-		r, err := checkRevocation(cert, baseCRL, time.Time{}, "")
+		r, err := checkRevocation(cert, &crlutils.Bundle{BaseCRL: baseCRL}, time.Time{}, "")
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -607,11 +829,91 @@ func TestCheckRevocation(t *testing.T) {
 				},
 			},
 		}
-		_, err := checkRevocation(cert, baseCRL, signingTime, "")
+		_, err := checkRevocation(cert, &crlutils.Bundle{BaseCRL: baseCRL}, signingTime, "")
 		if err == nil {
 			t.Fatal("expected error")
 		}
 	})
+
+	t.Run("delta crl with certificate hold", func(t *testing.T) {
+		baseCRL := &x509.RevocationList{}
+		deltaCRL := &x509.RevocationList{
+			RevokedCertificateEntries: []x509.RevocationListEntry{
+				{
+					SerialNumber: big.NewInt(1),
+					ReasonCode:   reasonCodeCertificateHold,
+				},
+			},
+		}
+		r, err := checkRevocation(cert, &crlutils.Bundle{BaseCRL: baseCRL, DeltaCRL: deltaCRL}, signingTime, "")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if r.Result != result.ResultRevoked {
+			t.Fatalf("expected revoked, got %s", r.Result)
+		}
+	})
+
+	t.Run("certificate hold and remove hold", func(t *testing.T) {
+		baseCRL := &x509.RevocationList{
+			RevokedCertificateEntries: []x509.RevocationListEntry{
+				{
+					SerialNumber:   big.NewInt(1),
+					ReasonCode:     reasonCodeCertificateHold,
+					RevocationTime: time.Now().Add(-time.Hour),
+				},
+			},
+		}
+		deltaCRL := &x509.RevocationList{
+			RevokedCertificateEntries: []x509.RevocationListEntry{
+				{
+					SerialNumber:   big.NewInt(1),
+					ReasonCode:     reasonCodeRemoveFromCRL,
+					RevocationTime: time.Now(),
+				},
+			},
+		}
+		r, err := checkRevocation(cert, &crlutils.Bundle{BaseCRL: baseCRL, DeltaCRL: deltaCRL}, signingTime, "")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if r.Result != result.ResultOK {
+			t.Fatalf("expected OK, got %s", r.Result)
+		}
+	})
+
+	t.Run("certificate hold, remove hold and hold again", func(t *testing.T) {
+		baseCRL := &x509.RevocationList{
+			RevokedCertificateEntries: []x509.RevocationListEntry{
+				{
+					SerialNumber:   big.NewInt(1),
+					ReasonCode:     reasonCodeCertificateHold,
+					RevocationTime: time.Now().Add(-2 * time.Hour),
+				},
+			},
+		}
+		deltaCRL := &x509.RevocationList{
+			RevokedCertificateEntries: []x509.RevocationListEntry{
+				{
+					SerialNumber:   big.NewInt(1),
+					ReasonCode:     reasonCodeRemoveFromCRL,
+					RevocationTime: time.Now().Add(-time.Hour),
+				},
+				{
+					SerialNumber:   big.NewInt(1),
+					ReasonCode:     reasonCodeCertificateHold,
+					RevocationTime: time.Now(),
+				},
+			},
+		}
+		r, err := checkRevocation(cert, &crlutils.Bundle{BaseCRL: baseCRL, DeltaCRL: deltaCRL}, signingTime, "")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if r.Result != result.ResultRevoked {
+			t.Fatalf("expected revoked, got %s", r.Result)
+		}
+	})
 }
 
 func TestParseEntryExtension(t *testing.T) {
@@ -737,6 +1039,19 @@ func TestSupported(t *testing.T) {
 	})
 }
 
+func TestHasDeltaCRL(t *testing.T) {
+	cert := &x509.Certificate{
+		Extensions: []pkix.Extension{
+			{
+				Id: oidFreshestCRL,
+			},
+		},
+	}
+	if !hasDeltaCRL(cert) {
+		t.Fatal("expected has delta CRL")
+	}
+}
+
 type errorRoundTripperMock struct{}
 
 func (rt errorRoundTripperMock) RoundTrip(req *http.Request) (*http.Response, error) {