diff --git a/common/hash_calculator.cc b/common/hash_calculator.cc
index de6e0f9..ebfdb6e 100644
--- a/common/hash_calculator.cc
+++ b/common/hash_calculator.cc
@@ -20,7 +20,6 @@
 
 #include <base/logging.h>
 #include <base/posix/eintr_wrapper.h>
-#include <brillo/data_encoding.h>
 
 #include "update_engine/common/utils.h"
 
@@ -37,7 +36,7 @@
 // Mostly just passes the data through to OpenSSL's SHA256_Update()
 bool HashCalculator::Update(const void* data, size_t length) {
   TEST_AND_RETURN_FALSE(valid_);
-  TEST_AND_RETURN_FALSE(hash_.empty());
+  TEST_AND_RETURN_FALSE(raw_hash_.empty());
   static_assert(sizeof(size_t) <= sizeof(unsigned long),  // NOLINT(runtime/int)
                 "length param may be truncated in SHA256_Update");
   TEST_AND_RETURN_FALSE(SHA256_Update(&ctx_, data, length) == 1);
@@ -73,16 +72,11 @@
 }
 
 // Call Finalize() when all data has been passed in. This mostly just
-// calls OpenSSL's SHA256_Final() and then base64 encodes the hash.
+// calls OpenSSL's SHA256_Final().
 bool HashCalculator::Finalize() {
-  TEST_AND_RETURN_FALSE(hash_.empty());
   TEST_AND_RETURN_FALSE(raw_hash_.empty());
   raw_hash_.resize(SHA256_DIGEST_LENGTH);
   TEST_AND_RETURN_FALSE(SHA256_Final(raw_hash_.data(), &ctx_) == 1);
-
-  // Convert raw_hash_ to base64 encoding and store it in hash_.
-  hash_ = brillo::data_encoding::Base64Encode(raw_hash_.data(),
-                                              raw_hash_.size());
   return true;
 }
 
@@ -115,21 +109,6 @@
   return res;
 }
 
-string HashCalculator::HashOfBytes(const void* data, size_t length) {
-  HashCalculator calc;
-  calc.Update(data, length);
-  calc.Finalize();
-  return calc.hash();
-}
-
-string HashCalculator::HashOfString(const string& str) {
-  return HashOfBytes(str.data(), str.size());
-}
-
-string HashCalculator::HashOfData(const brillo::Blob& data) {
-  return HashOfBytes(data.data(), data.size());
-}
-
 string HashCalculator::GetContext() const {
   return string(reinterpret_cast<const char*>(&ctx_), sizeof(ctx_));
 }
diff --git a/common/hash_calculator.h b/common/hash_calculator.h
index f749585..06d2cfb 100644
--- a/common/hash_calculator.h
+++ b/common/hash_calculator.h
@@ -27,11 +27,11 @@
 #include <base/macros.h>
 #include <brillo/secure_blob.h>
 
-// Omaha uses base64 encoded SHA-256 as the hash. This class provides a simple
-// wrapper around OpenSSL providing such a formatted hash of data passed in.
+// This class provides a simple wrapper around OpenSSL providing a hash of data
+// passed in.
 // The methods of this class must be called in a very specific order: First the
 // ctor (of course), then 0 or more calls to Update(), then Finalize(), then 0
-// or more calls to hash().
+// or more calls to raw_hash().
 
 namespace chromeos_update_engine {
 
@@ -50,17 +50,10 @@
   off_t UpdateFile(const std::string& name, off_t length);
 
   // Call Finalize() when all data has been passed in. This method tells
-  // OpenSSl that no more data will come in and base64 encodes the resulting
-  // hash.
+  // OpenSSL that no more data will come in.
   // Returns true on success.
   bool Finalize();
 
-  // Gets the hash. Finalize() must have been called.
-  const std::string& hash() const {
-    DCHECK(!hash_.empty()) << "Call Finalize() first";
-    return hash_;
-  }
-
   const brillo::Blob& raw_hash() const {
     DCHECK(!raw_hash_.empty()) << "Call Finalize() first";
     return raw_hash_;
@@ -83,15 +76,9 @@
   static off_t RawHashOfFile(const std::string& name, off_t length,
                              brillo::Blob* out_hash);
 
-  // Used by tests
-  static std::string HashOfBytes(const void* data, size_t length);
-  static std::string HashOfString(const std::string& str);
-  static std::string HashOfData(const brillo::Blob& data);
-
  private:
-  // If non-empty, the final base64 encoded hash and the raw hash. Will only be
-  // set to non-empty when Finalize is called.
-  std::string hash_;
+  // If non-empty, the final raw hash. Will only be set to non-empty when
+  // Finalize is called.
   brillo::Blob raw_hash_;
 
   // Init success
diff --git a/common/hash_calculator_unittest.cc b/common/hash_calculator_unittest.cc
index 436e6a7..233237b 100644
--- a/common/hash_calculator_unittest.cc
+++ b/common/hash_calculator_unittest.cc
@@ -22,6 +22,7 @@
 #include <string>
 #include <vector>
 
+#include <brillo/data_encoding.h>
 #include <brillo/secure_blob.h>
 #include <gtest/gtest.h>
 
@@ -33,9 +34,8 @@
 namespace chromeos_update_engine {
 
 // Generated by running this on a linux shell:
-// $ echo -n hi | openssl dgst -sha256 -binary | openssl base64
-static const char kExpectedHash[] =
-    "j0NDRmSPa5bfid2pAcUXaxCm2Dlh3TwayItZstwyeqQ=";
+// $ echo -n hi | openssl dgst -sha256 -binary |
+//   hexdump -v -e '"    " 12/1 "0x%02x, " "\n"'
 static const uint8_t kExpectedRawHash[] = {
   0x8f, 0x43, 0x43, 0x46, 0x64, 0x8f, 0x6b, 0x96,
   0xdf, 0x89, 0xdd, 0xa9, 0x01, 0xc5, 0x17, 0x6b,
@@ -52,7 +52,6 @@
   HashCalculator calc;
   calc.Update("hi", 2);
   calc.Finalize();
-  EXPECT_EQ(kExpectedHash, calc.hash());
   brillo::Blob raw_hash(std::begin(kExpectedRawHash),
                         std::end(kExpectedRawHash));
   EXPECT_TRUE(raw_hash == calc.raw_hash());
@@ -63,7 +62,6 @@
   calc.Update("h", 1);
   calc.Update("i", 1);
   calc.Finalize();
-  EXPECT_EQ(kExpectedHash, calc.hash());
   brillo::Blob raw_hash(std::begin(kExpectedRawHash),
                         std::end(kExpectedRawHash));
   EXPECT_TRUE(raw_hash == calc.raw_hash());
@@ -78,7 +76,6 @@
   calc_next.SetContext(calc_context);
   calc_next.Update("i", 1);
   calc_next.Finalize();
-  EXPECT_EQ(kExpectedHash, calc_next.hash());
   brillo::Blob raw_hash(std::begin(kExpectedRawHash),
                         std::end(kExpectedRawHash));
   EXPECT_TRUE(raw_hash == calc_next.raw_hash());
@@ -106,7 +103,8 @@
   //     echo -n $C
   //     let C=C+1
   //   done | openssl dgst -sha256 -binary | openssl base64
-  EXPECT_EQ("NZf8k6SPBkYMvhaX8YgzuMgbkLP1XZ+neM8K5wcSsf8=", calc.hash());
+  EXPECT_EQ("NZf8k6SPBkYMvhaX8YgzuMgbkLP1XZ+neM8K5wcSsf8=",
+            brillo::data_encoding::Base64Encode(calc.raw_hash()));
 }
 
 TEST_F(HashCalculatorTest, UpdateFileSimpleTest) {
@@ -121,7 +119,6 @@
     HashCalculator calc;
     EXPECT_EQ(2, calc.UpdateFile(data_path, kLengths[i]));
     EXPECT_TRUE(calc.Finalize());
-    EXPECT_EQ(kExpectedHash, calc.hash());
     brillo::Blob raw_hash(std::begin(kExpectedRawHash),
                           std::end(kExpectedRawHash));
     EXPECT_TRUE(raw_hash == calc.raw_hash());
@@ -132,7 +129,8 @@
   EXPECT_EQ(1, calc.UpdateFile(data_path, 1));
   EXPECT_TRUE(calc.Finalize());
   // echo -n h | openssl dgst -sha256 -binary | openssl base64
-  EXPECT_EQ("qqlAJmTxpB9A67xSyZk+tmrrNmYClY/fqig7ceZNsSM=", calc.hash());
+  EXPECT_EQ("qqlAJmTxpB9A67xSyZk+tmrrNmYClY/fqig7ceZNsSM=",
+            brillo::data_encoding::Base64Encode(calc.raw_hash()));
 }
 
 TEST_F(HashCalculatorTest, RawHashOfFileSimpleTest) {
diff --git a/common/utils.cc b/common/utils.cc
index ea748c1..f528660 100644
--- a/common/utils.cc
+++ b/common/utils.cc
@@ -944,8 +944,16 @@
   return str;
 }
 
-string CalculateP2PFileId(const string& payload_hash, size_t payload_size) {
-  string encoded_hash = brillo::data_encoding::Base64Encode(payload_hash);
+// The P2P file id should be the same for devices running new version and old
+// version so that they can share it with each other. The hash in the response
+// was base64 encoded, but now that we switched to use "hash_sha256" field which
+// is hex encoded, we have to convert them back to base64 for P2P. However, the
+// base64 encoded hash was base64 encoded here again historically for some
+// reason, so we keep the same behavior here.
+string CalculateP2PFileId(const brillo::Blob& payload_hash,
+                          size_t payload_size) {
+  string encoded_hash = brillo::data_encoding::Base64Encode(
+      brillo::data_encoding::Base64Encode(payload_hash));
   return base::StringPrintf("cros_update_size_%" PRIuS "_hash_%s",
                             payload_size,
                             encoded_hash.c_str());
diff --git a/common/utils.h b/common/utils.h
index 8cccc24..eaf2640 100644
--- a/common/utils.h
+++ b/common/utils.h
@@ -53,7 +53,7 @@
 std::string StringVectorToString(const std::vector<std::string> &vec_str);
 
 // Calculates the p2p file id from payload hash and size
-std::string CalculateP2PFileId(const std::string& payload_hash,
+std::string CalculateP2PFileId(const brillo::Blob& payload_hash,
                                size_t payload_size);
 
 // Parse the firmware version from one line of output from the