diff --git a/src/main/java/org/mskcc/cbio/oncokb/domain/Token.java b/src/main/java/org/mskcc/cbio/oncokb/domain/Token.java
index fa6c51606..009f19b9a 100644
--- a/src/main/java/org/mskcc/cbio/oncokb/domain/Token.java
+++ b/src/main/java/org/mskcc/cbio/oncokb/domain/Token.java
@@ -39,11 +39,11 @@ public class Token implements Serializable {
 
     @NotNull
     @Column(name = "current_usage", nullable = false)
-    private Integer currentUsage;
+    private Integer currentUsage = 0;
 
     @NotNull
     @Column(name = "renewable", nullable = false)
-    private Boolean renewable;
+    private Boolean renewable = true;
 
     @Convert(converter = TokenKeyConverter.class)
     @Column(name = "new_token")
diff --git a/src/main/java/org/mskcc/cbio/oncokb/domain/TokenKey.java b/src/main/java/org/mskcc/cbio/oncokb/domain/TokenKey.java
index f364fe8ae..ec3b54045 100644
--- a/src/main/java/org/mskcc/cbio/oncokb/domain/TokenKey.java
+++ b/src/main/java/org/mskcc/cbio/oncokb/domain/TokenKey.java
@@ -1,19 +1,19 @@
 package org.mskcc.cbio.oncokb.domain;
 
 import java.io.Serializable;
-import java.nio.ByteBuffer;
 import java.security.SecureRandom;
 import java.util.zip.CRC32;
 
+import org.apache.commons.lang3.StringUtils;
 import org.mskcc.cbio.oncokb.domain.enumeration.TokenType;
 
-import io.seruco.encoding.base62.Base62;
-
 public class TokenKey implements Serializable {
     public static int TOKEN_CHAR_LENGTH = 30;
 
     public static int CHECKSUM_CHAR_LENGTH = 6;
 
+    private static String BASE62_CHARS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
+
     private TokenType tokenType;
 
     private String token;
@@ -24,24 +24,40 @@ public static TokenKey generate(TokenType type) {
         TokenKey tokenKey = new TokenKey();
         tokenKey.setTokenType(type);
         
-        Base62 base62 = Base62.createInstance();
-        SecureRandom secureRandom = new SecureRandom();
+        CRC32 crc32 = new CRC32();
 
-        byte[] bytes = new byte[24];
-        secureRandom.nextBytes(bytes);
-        String token = new String(base62.encode(bytes));
+        String token = generateToken();
         tokenKey.setToken(token);
 
-        CRC32 crc32 = new CRC32();
-        crc32.update(bytes);
-        ByteBuffer buffer = ByteBuffer.allocate(Long.BYTES);
-        buffer.putLong(crc32.getValue());
-        String checksum = new String(base62.encode(buffer.array()));
-        tokenKey.setChecksum(checksum.substring(checksum.length() - TokenKey.CHECKSUM_CHAR_LENGTH));
+        crc32.update(token.getBytes());
+        String base62Checksum = toBase62(crc32.getValue());
+        if (base62Checksum.length() < CHECKSUM_CHAR_LENGTH) {
+            base62Checksum = StringUtils.repeat('0', CHECKSUM_CHAR_LENGTH - base62Checksum.length());
+        }
+        tokenKey.setChecksum(base62Checksum);
 
         return tokenKey;
     }
 
+    private static String generateToken() {
+        SecureRandom secureRandom = new SecureRandom();
+        StringBuilder token = new StringBuilder();
+        for (int i = 0; i < TOKEN_CHAR_LENGTH; i++) {
+            token.append(BASE62_CHARS.charAt(secureRandom.nextInt(BASE62_CHARS.length())));
+        }
+        return token.toString();
+    }
+
+    public static String toBase62(long val) {
+        StringBuffer sb = new StringBuffer();
+        while(val > 0) {
+            int remainder = (int) (val % 62);
+            val = val / 62;
+            sb.insert(0, BASE62_CHARS.charAt((int) remainder));
+        }
+        return sb.toString();
+    }
+
     public boolean validateChecksum() {
         return false;
     }
diff --git a/src/test/java/org/mskcc/cbio/oncokb/domain/TokenKeyTest.java b/src/test/java/org/mskcc/cbio/oncokb/domain/TokenKeyTest.java
new file mode 100644
index 000000000..c4a25a1da
--- /dev/null
+++ b/src/test/java/org/mskcc/cbio/oncokb/domain/TokenKeyTest.java
@@ -0,0 +1,31 @@
+package org.mskcc.cbio.oncokb.domain;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.nio.ByteBuffer;
+
+import org.apache.commons.lang3.StringUtils;
+import org.junit.Test;
+
+public class TokenKeyTest {
+    @Test
+    public void toBase62() {
+        String test = "d";
+        assertThat(TokenKey.toBase62(stringToLong(test))).isEqualTo("1c");
+
+        test = "hello";
+        assertThat(TokenKey.toBase62(stringToLong(test))).isEqualTo("7tQLFHz");
+
+        test = "oncokb";
+        assertThat(TokenKey.toBase62(122519905332066L)).isEqualTo("Yn1xclvu");
+    }
+
+    private long stringToLong(String str) {
+        if (str.length() < Long.BYTES) {
+            str = StringUtils.repeat('\0', Long.BYTES - str.length()) + str;
+        }
+
+        ByteBuffer buffer = ByteBuffer.wrap(str.getBytes());
+        return buffer.getLong(0);
+    }
+}